JP2018103254A - Bottle can, capped bottle can, and manufacturing method for the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bottle can capable of surely preventing the mouthpiece from buckling upon applying a load in parallel with a can axis when the cap is mounted, a capped bottle can, and a manufacturing method for the same.SOLUTION: A bottle can comprises a shoulder keeping the diameter reduced toward the upper end side from the body of a bottomed cylindrical can body centered on the can axis, a neck extending from the shoulder toward the upper end side, and a mouthpiece having a male screw formed on the upper end side of the neck and a curl formed on the upper end side of the male screw, where the curl has a bend region so bent as to fold the upper end of the can body to the outer peripheral side and a flat region extending from the bent region toward the lower end side almost in parallel with the can axis, the outer surface of the bent region is 150 μm or more and 250 μm or less in a length parallel with the can axis from an apex on the upper end side of this bent region to a boundary with the flat region.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bottle can in which a curl portion is formed in a base portion, a bottle can with a cap in which a cap is attached to the bottle can, and a method for manufacturing the same.

  The bottle can has a curl portion in which the tip portion is folded back in the outer peripheral direction in the base portion. Such a curled portion has a bent region where the upper end portion of the can body is bent so as to be folded back to the outer peripheral side, and a flat region extending from the bent region toward the lower end side substantially parallel to the can axis. .

When manufacturing a bottle can with a cap by attaching a cap to such a bottle can, the bottomed cylindrical cap material with a sealing material on the inside is put on the base of the bottle can, and it is placed on the periphery of the top plate of the cap material. On the other hand, a step is formed by applying a load parallel to the can axis (capping). As a result, the curl portion of the bottle can adheres to the sealing material, and the bottle can is kept liquid-tight. Thereafter, the rotating tool is pressed against the outer surface of the peripheral wall of the cap material, and the cap threaded bottle can is manufactured by forming the female thread portion in accordance with the shape of the male thread portion formed in the cap portion on the cap material. (See Patent Document 1).
In recent years, in order to reduce the weight and the manufacturing cost of such bottle cans, it has been desired to reduce the thickness of the can body.

Japanese Patent Laid-Open No. 2006-137915

  However, if the thickness of the can body of the bottle can is reduced for weight reduction and manufacturing cost reduction, the thickness is reduced when a load is applied parallel to the can axis in the step of forming the stepped portion in the cap material described above. There was a problem that the curled portion was likely to buckle due to insufficient strength. On the other hand, in order to prevent such buckling, if the load applied in parallel to the can axis is reduced in the step of forming the stepped portion in the cap material, the adhesion between the curled portion and the sealing material is reduced, and the bottle can There is a concern that the liquid contained in the tank may leak.

  The present invention has been made under such a background. A bottle can and cap that can reliably prevent the base from buckling when a load is applied parallel to the can axis when the cap is attached. It is an object of the present invention to provide an attached bottle can and a manufacturing method thereof.

  In order to solve the above-mentioned problems and achieve such an object, the bottle can of the present invention has a shoulder whose diameter is reduced from the body part of the bottomed cylindrical can body centering on the can axis toward the upper end side. A neck portion extending from the shoulder portion toward the upper end side, a male screw portion formed on the upper end side of the neck portion, and a base portion having a curl portion formed on the upper end side of the male screw portion. The curled portion is connected to the male screw portion, and is bent so that the upper end portion of the can body is folded back to the outer peripheral side; A flat region extending in parallel toward the lower end side, and the outer surface of the bent region has a length parallel to the can axis from the top of the upper end side of the bent region to the boundary with the flat region is 150 μm. As described above, it is 250 μm or less.

  In order to improve the sealing performance by bringing the sealing member into close contact with the curled portion, the length (side seal length: SSL) that is in close contact with the sealing member in the flat region is important. By lengthening such SSL, for example, when the inside of the bottle can is set to a positive pressure, the cap is lifted, whereby the adhesion between the flat region and the seal member is enhanced.

  In the bottle can of the present invention, by setting the length parallel to the can axis from the top of the curled part to the boundary with the flat region to be 150 μm or more, the position of the boundary between the bent region and the flat region of the curled part is appropriately set. It is possible to prevent the breakage of the sealing member caused by such a boundary being raised upwards.

  The bottle can of the present invention has a boundary between the bent region and the flat region in the curled portion of the bottle can by making the length parallel to the can axis from the top of the curled portion to the boundary with the flat region not more than 250 μm. The position of the seal member can be appropriately maintained, and the length of the seal member can be increased in a flat region, and the adhesion of the seal member to the curled portion can be kept high and the sealing performance of the curled portion can be improved. Can do.

  In addition, since the length parallel to the can axis in the flat region can be increased, the axial load (torque) applied during capping can be reduced, and sealing with a cap can be performed with a small axial load torque. The buckling of the mouthpiece of the bottle can can be reliably prevented.

  Further, in the bottle can of the present invention, the boundary between the bent region and the flat region is an intersection with a portion where bending starts at a curvature radius of 10 times or more of the curvature radius of the bent region on the upper end side of the flat region. It is characterized by being.

  A bottle can with a cap according to the present invention is a peripheral wall in which the bottle can described in the above-mentioned items, a top plate portion covering the curl portion, and the male screw portion are formed and a female screw portion is formed to be screwed into the male screw portion. And a sealing member formed on the inner surface side of the cap and in close contact with the bent region and the flat region of the curled portion.

  The method for producing a bottle can with a cap according to the present invention is a method for producing a bottle can with a cap according to the preceding paragraph, wherein the bottle can is covered with a bottomed cylindrical cap material having a top plate and a peripheral wall. Applying a load to the periphery of the top plate in parallel to the can axis to form a step portion forming step for forming the top plate portion with a step portion; and pressing the rotary tool against the outer surface of the peripheral wall, An internal thread portion forming step of forming a peripheral wall portion having an internal thread portion following the shape of the portion, and in the stepped portion forming step, a load applied in a direction parallel to the can shaft is 900 N or less It is characterized by.

  According to the present invention, there are provided a bottle can, a bottle can with a cap, and a method for manufacturing the same that can reliably prevent the base from buckling when a load is applied in parallel to the can axis when the cap is attached. can do.

It is a partially broken side view showing one embodiment of the bottle can of the present invention. It is a principal part expanded sectional view which shows the curl part formed in the nozzle | cap | die part of the bottle can of this invention. It is a principal part expanded sectional view which shows the curl part formed in the nozzle | cap | die part of the conventional bottle can. It is a principal part expanded sectional view which shows the nozzle | cap | die part of the bottle can with a cap which is one Embodiment of this invention. It is a principal part expanded sectional view which shows the curl part of FIG. 4, and its vicinity.

  Hereinafter, a bottle can, a bottle can with a cap, and a manufacturing method thereof according to an embodiment of the present invention will be described with reference to the drawings. The following embodiments are specifically described for better understanding of the gist of the invention, and do not limit the present invention unless otherwise specified. In addition, in the drawings used in the following description, in order to make the features of the present invention easier to understand, there is a case where a main part is shown in an enlarged manner for convenience, and the dimensional ratio of each component is the same as the actual one. Not necessarily.

FIG. 1 is a partially broken side view showing a bottle can according to an embodiment of the present invention.
The bottle can 1 of the present embodiment is centered on a can shaft C having a bottom portion 2 and an outer peripheral portion 3 formed integrally with the bottom portion 2 and extending from the outer peripheral edge of the bottom portion 2 to the upper end side (upper side in FIG. 1). It has the can main body 11 which consists of a substantially multistage bottomed cylindrical shape.

  A dome portion 2a having a substantially arc-shaped cross-section that is recessed inward in the can axis C direction (upper end side of the can body 11) is formed in the bottom 2 at the center, and the outer periphery of the dome portion 2a is in the can axis C direction. An annular convex portion 2b that protrudes outward (the lower end side of the can body 11) is formed continuously in the circumferential direction around the can axis C.

In addition, the outer peripheral portion 3 has a cylindrical body portion 5 centering on the can axis C in order from the bottom portion 2 to the opening portion 4 on the upper end side of the can body 11, and gradually with a certain inclination toward the upper end side. A frustoconical shoulder 6 having a reduced diameter, a cylindrical neck 7 extending further from the shoulder 6 toward the upper end, a bulging portion 8 projecting from the upper end of the neck 7 to the outer peripheral side, and a male screw portion 9 and a curled portion 10 are formed.
A portion including the bulging portion 8, the male screw portion 9, and the curled portion 10 above the neck portion 7 constitutes the base portion 12.

  In order to manufacture such a bottle can, first, a cup-shaped material with a shallow depth is manufactured by punching a metal plate such as aluminum or aluminum alloy into a disk shape and performing a drawing process in a cupping press process by a cupping press machine. To do. Next, the cup-shaped material is subjected to redrawing and ironing in a DI press process by a DI press machine and stretched in the direction of the can axis C, whereby the dome portion 2a and the annular convex portion 2b are formed on the bottom portion 2. A bottom cylinder (DI can) is formed.

In this embodiment, the metal plate formed into a cup-shaped material in the cupping press process is an aluminum alloy plate of A3004 or A3104 in JIS H 4000 having a base plate thickness of 0.285 mm to 0.300 mm, and is 205 ° C. × 20. A 0.2% proof stress after minute baking is in the range of 235 N / mm ^{2 to} 265 N / mm ² .

  Further, the bottomed cylindrical body formed from the cup-shaped material has a cylindrical portion centered on the can axis C on the outer peripheral portion, and the outer diameter of the cylindrical portion is outside the body portion 5 of the can body 11. A constant outer diameter substantially equal to the diameter.

  The bottomed cylindrical body formed in this way is cleaned and dried in the first cleaning step, and then the inner and outer surfaces are painted and baked in the coating step. In the bottled neck forming step by the bottle necker, the bottomed cylindrical body that has been coated is reduced in diameter by the mold at the lower end side of the upper end side portion of the cylindrical portion, and the shoulder portion 6 and the neck portion 7 are formed. .

  Next, the upper end side of the neck portion 7 is expanded by a diameter expanding tool to form the bulging portion 8, and the threading process is further performed on the upper end side of the bulging portion 8 to form the male screw portion 9. The Next, the upper end side of the male screw portion 9 is folded back and curled, and then crushed by throttle processing to form a curled portion 10, which is formed into a can body 11 of a bottle can as shown in FIG. .

  After the can body 11 thus molded is cleaned and dried in the second cleaning process, the inspection process is inspected for the presence of pinholes, adhesion of foreign matters on the outer surface, scratches, dirt, printing defects, etc. After being transported and filled with contents such as beverages, a cap 11 is attached and sealed from the curled portion 10 to the male screw portion 9 and the bulging portion 8 so as to cover the opening 4 as shown in FIG. Shipped. In addition, during each process of the can main body 11 or during each process, trimming that cuts the upper edge of the bottomed cylindrical body, or bottom reform that reshapes the cross-sectional shape of the bottom annular projection 2b as necessary Is done.

FIG. 2 is an enlarged cross-sectional view of a main part showing a curled part formed in a base part of a bottle can.
As shown in FIG. 2, the curled portion 10 is connected to the male screw portion 9 (see FIG. 1) and is bent so that the upper end portion of the can body 11 is bent back to the outer peripheral side, and the bent region 10A. And a flat region 10B extending toward the lower end side (lower side in FIG. 1) of the can body 11 substantially in parallel to the can axis C (see FIG. 1).

  The outer surface of the bent region 10A of the curled portion 10 is a length parallel to the can axis C from the top T1 to the boundary between the flat region 10B (the boundary between the bent region 10A and the flat region 10B on the outer surface of the can body 11) E1. Is formed to be 150 μm or more and 250 μm or less.

  For example, the boundary E1 between the bent region 10A and the flat region 10B of the curled portion 10 has a radius of curvature that is 10 times or more of the radius of curvature r1 of the circle R1 that forms the outer surface of the bent region 10A on the upper end side of the outer surface of the flat region 10B. It is considered as the intersection with the part where bending begins. The arc indicated by R2 in FIG. 2 indicates a part of a circle having a radius of curvature 10 times that of the circle R1. The cross-sectional shape of the flat region 10B is substantially the same as that of the can axis C, which is composed of an arc that is almost a straight line with a radius of curvature of 10 times or more of the radius of curvature of the bent region 10A, a straight line parallel to the can axis C, or both. It is a parallel region.

  As an example, the curled portion 10 shown in FIG. 2 has a curvature radius r1 = 0.54 mm of the outer surface of the bent region 10A. A length L1 parallel to the can axis C from the top T1 of the outer surface of the bent region 10A to the boundary E1 on the outer surface of the bent region 10A and the flat region 10B is 200 μm.

  On the other hand, the curled portion 101 in the conventional bottle can 100 shown in FIG. 3 in which the wall thickness of the can body is thicker than that of the present embodiment has a curvature radius r2 = 0.65 mm of the outer surface of the bent region 101A. A length L2 parallel to the can axis C from the top T2 of the outer surface of the bent region 101A to the boundary E2 on the outer surface of the bent region 101A and the flat region 101B is 320 μm.

  Thus, in the bottle can 1 of the present embodiment, the position of the boundary E1 between the bent region 10A and the flat region 10B in the curled portion 10 is closer to the upper end side than the position of the boundary E2 of the conventional bottle can 100. The length of the flat region 10B parallel to the can axis C is increased accordingly. By increasing the length of the flat region 10B parallel to the can axis C, adhesion to a seal member described later can be improved.

FIG. 4 is an enlarged cross-sectional view showing a main part of a cap portion of a bottle can with a cap according to an embodiment of the present invention. FIG. 5 is an enlarged cross-sectional view of the main part showing the curled part of FIG. 4 and the vicinity thereof.
A bottle can 20 with a cap according to an embodiment of the present invention includes the bottle can 1 shown in FIGS. 1 and 2 and a cap 21 attached to a base portion 12 of the bottle can 1.

  The cap 21 is formed by integrally forming a top plate portion 22 that covers the curled portion 10 of the can body 11 and a peripheral wall portion 23 that covers the male screw portion 9. The peripheral wall portion 23 is formed with a female screw portion 24 that is screwed into the male screw portion 9. By such a male screw portion 9 formed on the can body 11 and a female screw portion 24 formed on the cap 21, the cap can be opened and closed (resealed) even after the cap 21 is opened.

  A step portion 25 is formed on the periphery of the top plate portion 22. A seal member (sealing liner) 26 is sandwiched between the inner surface 21 a of the cap 21 and the curled portion 10. The seal member 26 accommodates a liquid such as a beverage inside the bottle can 1, and closes the gap between the curled portion 10 and the inner surface 21 a of the cap 21 when the base portion 12 is covered with the cap 21. Prevent leakage.

  The step portion 25 is formed by pressing the top plate portion 22 by the pressure block of the capping device. As a result, the seal member 26 comes into close contact with the flat region 10B from the bent region 10A constituting the curled portion 10.

  In order to improve the sealing performance by bringing the sealing member into close contact with the curled portion, the length (side seal length: SSL) that is in close contact with the sealing member 26 in the flat region 10B is important. By lengthening such SSL, for example, when the inside of the bottle can 1 is set to a positive pressure, the cap 21 is lifted, whereby the adhesion between the flat region 10B and the seal member 26 is enhanced.

  In the bottle can 20 with a cap that is one embodiment of the present invention, the length parallel to the can axis C from the top T1 of the curled portion 10 of the bottle can 1 to the boundary E1 between the bent region 10A and the flat region 10B is 150 μm or more. By doing so, the position of the boundary between the bent region 10A and the flat region is appropriately maintained, and the seal member is prevented from being broken when the boundary is excessively raised, so that the adhesion to the curled portion 10 is kept high. Can do.

  In addition, the bottle can 20 with the cap has a length parallel to the can axis C from the top portion T1 of the curled portion 10 of the bottle can 1 to the boundary E1 between the bent region 10A and the flat region 10B, which is 250 μm or less. The position of the boundary E1 between the bent region 10A and the flat region 10B in the curled portion 10 of the can 1 can be raised to the upper end side than the conventional bottle can. Thereby, the length parallel to the can axis | shaft C of the flat area | region 10B with which the sealing member 26 can contact | connect stably can be lengthened, and the adhesiveness to the curl part 10 of the sealing member 26 can be kept high. .

  As a method for manufacturing a bottle can with a cap according to an embodiment of the present invention, when the cap 21 is attached to the can body 11 of the bottle can 1, a disk-shaped top plate made of aluminum or an aluminum alloy is used, as is the case with the can body 11. A bottomed cylindrical cap material integrally provided with a cylindrical peripheral wall extends from the curled portion 10 to the male screw portion 9 and the bulging portion 8 so as to close the opening portion 4 of the can body 1 with the opening portion facing downward. It is put over. A seal member 26 is disposed in advance on the inner surface side of the top plate.

  Then, for example, the top plate of the cap material is pressed against the curled portion 10 by the pressure block of the capping device and is drawn to form a step portion 25 on the periphery of the top plate. Thus, the top plate portion 22 having the step portion 25 is obtained (step portion forming step). By such a stepped portion forming step, the seal member 26 previously disposed on the inner surface side of the top plate is in close contact with the curled portion 10 from the bent region 10A to the flat region 10B. At this time, the load applied in the direction parallel to the can axis by the pressure block is set to 900 N or less.

  The load due to the pressure block in the conventional stepped portion forming step was 1000 N or more. However, in the method for manufacturing a bottle can with a cap according to the present invention, the load applied in the direction parallel to the can axis by the pressure block is conventionally increased. By setting it to 900 N or less which is also low, buckling of the cap part 12 of the bottle can 1 can be reliably prevented.

On the other hand, there is a concern that the adhesion force of the sealing member to the curled portion may be reduced by reducing the load due to the pressure block in the step portion forming step. However, in the bottle can 20 with a cap of the present invention, the curled portion of the bottle can 1 is used. The length parallel to the can axis C from the top T1 of 10 to the boundary E1 between the bent region 10A and the flat region 10B is 250 μm or less, whereby the bent region 10A and the flat region 10B in the curled part 10 of the bottle can 1 are The position of the boundary E1 can be raised to the upper end side of the conventional bottle can.
Thereby, the position of the boundary between the bent region 10A and the flat region 10B in the curled portion 10 of the bottle can 20 is appropriately maintained, and the length in close contact with the seal member 26 in the flat region 10B can be increased. And the sealing property of the curled portion can be improved. Thereby, for example, even if the load applied in the direction parallel to the can axis by the pressure block is 900 N or less which is lower than the conventional one, the adhesion of the sealing member 26 to the curled portion 10 does not deteriorate.

Along with such a stepped portion forming step, a rotating tool such as a screw processing roll is pressed against the peripheral wall and is subjected to screw processing so as to follow the male screw portion 9, whereby a female screw portion 24 is formed on the inner periphery and A peripheral wall portion 23 in which the lower end edge of the peripheral wall is wound around the bulging portion 8 by the winding roll is formed (internal thread portion forming step).
Through the above steps, a bottle can 20 with a cap according to an embodiment of the present invention is manufactured.

  As mentioned above, although embodiment of this invention was described, these embodiment is shown as an example and is not intending limiting the range of invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and modifications thereof are included in the invention described in the claims and equivalents thereof in the same manner as included in the scope and gist of the invention.

Hereinafter, verification examples for verifying the effects of the present invention will be described.
A drop leak test and a reseal torque test were conducted on Examples (present invention examples) 1 and 2 and Comparative Examples (conventional examples) 1, 2 and 3 under the conditions shown in Table 1.
In Table 1, W (μm) is the plate thickness at the curled portion of the can body. L (μm) is a length parallel to the can axis from the top of the outer surface of the bent region to the boundary at the outer surface of the bent region and the flat region. TP (N) is a load due to the pressure block in the step portion forming process. Furthermore, SSL (mm) is a length in which the outer peripheral portion of the seal member (liner) deformed by shoulder drawing is in close contact with the outside of the base portion.

(Fall leak test)
The number of evaluation cans was 10 cans. A bottle with a cap that has been allowed to stand for 1 day after the retort treatment is dropped in an inverted (vertical) posture on an iron plate tilted by 10 ° from a height of 30 cm, and then placed in an upright position and left for 1 day. Measure the internal pressure before and after the drop, and determine that a leak has occurred when the pressure has dropped by 30 kPa or more. It was.

(Reseal torque)
The number of evaluation cans was 10 cans. After opening the bottle can with cap once, the maximum torque required when resealing by returning to 30 ° before the original position is measured, and there is one can whose maximum torque is 10 N · cm or more The case was determined as “NG”, and the case where the maximum torque of all 10 cans was less than 10 N · cm was determined as “PASS”.

According to the results shown in Table 1, by setting L to 150 μm or more and 250 μm or less and TP to 900 N or less, good results were obtained in both the drop leak test and reseal torque.
On the other hand, in Comparative Example 1 in which TP was 1000 N, the male screw portion of the base portion was buckled, and the torque necessary for resealing was too large. Further, in Comparative Example 2 in which L was set to 324, SSL was too short, and the adhesion of the seal member was insufficient, resulting in liquid leakage. Furthermore, in Comparative Example 3 in which L was set to 120, the curled portion was close to an acute angle, the seal member was cut, the adhesion was insufficient, and liquid leakage occurred.

DESCRIPTION OF SYMBOLS 1 Bottle can 9 Male thread part 10 Curled part 10A Bending area 10B Flat area 12 Cap part 21 Cap 22 Top plate part 23 Peripheral wall part C Can axis

Claims (4)

It is formed on the upper end side of the neck part, the shoulder part which is diameter-reduced as it goes from the trunk part of the bottomed cylindrical can body centering on the can axis toward the upper end side, the neck part extending from the shoulder part toward the upper end side. A bottle can comprising a male screw part and a cap part having a curl part formed on the upper end side of the male screw part,
The curled portion is connected to the male screw portion and is bent so that the upper end portion of the can body is folded back to the outer peripheral side, and the bent portion is directed substantially toward the lower end side substantially parallel to the can axis. An extending flat region,
The bottle can characterized in that the outer surface of the bent region has a length parallel to the can axis from the top on the upper end side of the bent region to the boundary with the flat region is 150 μm or more and 250 μm or less.   The boundary between the bent region and the flat region is an intersection with an upper end side of the flat region and a portion where bending starts at a curvature radius of 10 times or more of the curvature radius of the bent region. 1. The bottle can according to 1.   A bottomed cylindrical shape having a bottle can according to claim 1 or 2, and a peripheral wall portion formed with a top plate portion covering the curled portion and a female screw portion covering the male screw portion and screwing into the male screw portion. A bottle can with a cap, comprising: a cap; and a seal member formed on an inner surface side of the cap and in close contact with the bent region and the flat region of the curled portion. It is a manufacturing method of the bottle can with a cap according to claim 3,
The top plate provided with a stepped portion by applying a bottomed cylindrical cap material having a top plate and a peripheral wall to the bottle can on the base portion, applying a load in parallel to the can axis to the periphery of the top plate A step portion forming step for forming a portion and a female screw portion forming step for forming a peripheral wall portion having a female screw portion following the shape of the male screw portion by pressing a rotary tool against the outer surface of the peripheral wall. And
In the step portion forming step, a load applied in a direction parallel to the can axis is set to 900 N or less.

Images