JP5735319B2 - Double lid can lid - Google Patents

Description

  The present invention relates to a double winding can lid that is attached to an opening end of a can body by double winding.

  2. Description of the Related Art Conventionally, a can filled with a soft drink or the like employs a structure in which the outer periphery of a can lid is double-rolled around an opening of a bottomed cylindrical can body (see Patent Document 1). Such a double tightening portion of the can has a flange portion formed in advance at the opening end portion of the can body, and a curl portion is formed in the outer peripheral portion of the can lid, and the can lid is formed on the flange portion of the can body. The curled part of the can lid is curled together on the outside, and the curled part of the can lid is rolled up so that the curled part is folded back from the outside of the flange part of the can body. It is formed by pressing so as to crush from the outside. In addition, the sealing property of the container is maintained because the compound is filled between the can body and the can lid in this double winding part.

  Specifically, on the can body side, a body hook formed by folding back the flange portion is formed radially outward of the body portion from the upper end toward the lower side, and on the can lid side, the body hook is formed in the neck portion of the can body. A seaming panel that covers the folded portion of the upper end of the body hook continues from the upper end of the chuck wall that has entered, and a seaming wall that extends downward from the outer peripheral edge of the seaming panel is disposed radially outward of the body hook. A cover hook that is folded back from the lower end edge of the mining wall in a bowl shape and enters from the lower portion between the body hook and the neck portion of the can body has a structure extending upward.

  As a can lid having such a double winding structure, Patent Document 2 discloses a structure in which the wrapping property of the cover hook is improved. In the can lid of Patent Document 2, the cover hook is formed with a curved portion having two stages of curvature radii R1 and R2, and the curvature radius R2 of the second curved portion near the peripheral portion is set to the radius of curvature of the first curved portion near the center portion. It is formed smaller than the curvature radius R1. Similarly, Patent Document 3 to Patent Document 5 also disclose a can lid having a double tightening structure in which the winding property is improved by reducing the radius of curvature of the curved portion near the periphery of the cover hook. ing.

JP 2004-331139 A JP 2002-172446 A Japanese Patent Laid-Open No. 1-167050 JP 2002-102972 A JP 2008-73721 A

However, as described in Patent Document 2 to Patent Document 5, when the radius of curvature of the curved portion near the peripheral portion of the cover hook is made smaller than that of the curved portion near the central portion, the winding property at the time of tightening However, since the cover hook cannot be squeezed sufficiently between the body hook and the neck portion of the can body, there is a possibility that the portion may be scratched or cleaved to impair the sealing performance.
In recent years, it has been required to reduce the thickness of the can lid material in order to reduce the cost. If the thickness of the can lid material is reduced as it is without changing the shape of the can lid, it is difficult to entrain the can lid. Since it becomes sufficient, it becomes easy to generate | occur | produce winding fault, and there exists a possibility that sealing performance may fall.

  The present invention has been made in view of such circumstances, and even when a thin can lid material is used, a double-winding structure that can ensure sufficient sealing performance as a double-winding structure. Provide a can lid for fastening.

The can lid of the present invention is formed by molding an aluminum plate material having a thickness of 0.210 mm or more and 0.230 mm or less, and between a body hook folded at the upper end of a cylindrical can body and the neck of the can body. Further, a double-clamping can lid, in which a continuous cover hook enters from the lower end of the seaming wall radially outward of the body hook via a cover hook radius and is double-clamped, is disc-shaped A panel wall, a chuck wall provided on the outer edge of the panel section so as to continuously extend upward through a counter sink, and expands radially outward from the upper portion of the chuck wall, and then folded downward. A shoulder portion extending radially inward and covering the opening end of the can body, and a curl portion formed by folding the outer peripheral edge downward and radially from the shoulder portion And the curl portion is formed to have a cover hook radius, a cover hook radius portion corresponding to a portion constituting the cover hook, and a cover hook portion when the curl portion is wound around the can body. The cover hook portion includes a straight portion within a range of 0.2 mm from a tip thereof, a first curved portion located on a tip side excluding the straight portion, the first curved portion, and the cover hook radius portion. And the radius of curvature of the outer peripheral surface of the second curved portion is 0.6 mm to 1.1 mm, and the radius of curvature of the outer peripheral surface of the first curved portion , the second curved portion is large Ri by the radius of curvature of the outer peripheral surface of, and is formed into a 1.4mm or less, the radius of curvature of the outer peripheral surface of the cover hook radius portion is 1.2 mm or more 2.1mm or less It is formed in And features.

By configuring the cover hook portion as described above, sufficient sealing performance can be ensured even in a double-winding can using a thin can lid material.
In this case, the curvature of the outer peripheral surface of the first curved portion radius, by being also greater Ri by the radius of curvature of the outer peripheral surface of the second curved portion, it is possible to reduce the flexural rigidity of the first bending portion The cover hook portion can be reliably crushed and the sealing performance can be improved.
If the curvature of the outer peripheral surface of the first curved portion radius smaller than the radius of curvature of the outer peripheral surface of the second curved portion, the bending stiffness of the first curved portion is increased, also the radius of curvature of the outer peripheral surface of the second curved portion 0 If it is less than .6 mm, the bending rigidity of the second curved portion becomes high, and it becomes difficult to crush the cover hook portion to form a straight line, so that the sealing performance may be impaired. Further, when the radius of curvature of the outer peripheral surface of the second curved portion is larger than 1.1 mm, or when the radius of curvature of the outer peripheral surface of the first curved portion is larger than 1.4 mm, the cover hook portion is Since the front end portion of the can strongly hit the body portion of the can body and proper winding cannot be performed, the sealing performance may be impaired.
Further, when the radius of curvature of the outer peripheral surface of the cover hook radius portion is smaller than 1.2 mm, the winding of the tip of the cover hook portion becomes large, the compound of the upper clearance portion is pushed out, and the compound may be protruded. Moreover, when the curvature radius is larger than 2.1 mm, the shape freezing property after winding tightening deteriorates, there exists a possibility that the lower part of a winding fastening part may open and sealing performance may fall.

  According to the double winding can lid of the present invention, even when a thin can lid material is used, it is possible to ensure a sufficient sealing property as a double winding structure without fail.

It is principal part sectional drawing which shows the curl part of the can lid | cover for double winding based on this invention. It is a longitudinal cross-sectional view which shows the principal part of the can lid | cover for double winding fastening which concerns on this invention, and a can body, (a) shows before winding fastening, (b) shows after winding fastening. It is a half sectional view showing the can lid for double winding according to the present invention. It is principal part sectional drawing which shows the can lid | cover and can body for double winding after the winding shown in FIG.2 (b). It is a front view of the apparatus which performs the impact test of the double winding part of a drink can.

  Hereinafter, an embodiment of a double winding can lid according to the present invention will be described. The double winding can lid (hereinafter, “can lid”) 10 of the present embodiment is formed in a shape in which an outward flange portion 22 is continuous with an upper end of a bottomed cylindrical neck portion 21 made of aluminum alloy. Double winding is performed on the opening of the can body 20 (see FIG. 2).

  The can lid 10 is formed by pressing an aluminum alloy lid material having a base plate thickness of 0.210 mm or more and 0.230 mm or less, and enters the inside of the can body 20 as shown in FIGS. A panel portion 11 having a smaller diameter than the neck portion 21 of the body 20, a chuck wall 13 provided so as to extend upward from the outer edge portion of the panel portion 11 via the counter sink 12, and a radially outward direction from the upper end of the chuck wall 13 The shoulder portion 14 is formed so as to cover the opening end portion of the can body 20 and the curl portion 15 formed by folding the outer peripheral edge downward and radially toward the shoulder portion 14. A compound 30 is applied to the inner surface of the curled portion 15.

In the can lid 10, the shoulder portion 14 and the curl portion 15 extend radially outward from the upper portion of the chuck wall 13, and then are folded downward to extend radially inward (that is, toward the can body 20). The cross section is formed in a C-shape, and after tightening, as will be described later, a seaming panel radius 41, a seaming panel 42, a seaming wall radius 43, a seaming wall 44, a cover hook radius 45, and a cover hook 46 is configured (see FIG. 4). As shown in FIG. 1, the curled portion 15 includes a cover hook radius 45 and a cover hook radius portion 55 corresponding to the cover hook 46 and a cover hook portion 56 after winding.
The cover hook portion 56 located at the tip of the curled portion 15 includes a straight portion 56a within a range of 0.2 mm from the tip, a first bending portion 56b located on the tip side excluding the straight portion 56a, and a first bending portion. 56b and the cover hook radius part 55, and is comprised by the 2nd curved part 56c. The radius of curvature R2 of the second curved portion 56c is formed to be not less than 0.6 mm and not more than 1.1 mm, and the radius of curvature R1 of the first curved portion 56b is the same as the radius of curvature R2 of the second curved portion 56c. And is formed to be 1.4 mm or less.
Further, the curvature radius R3 of the cover hook radius portion 55 is formed to be 1.2 mm or more and 2.1 mm or less. The curvature radius R4 of the seaming wall portion 54 connected to the cover hook radius portion 55 is the same as or larger than the curvature radius R1 of the first curved portion 56b, and is formed to be 3.4 mm or less.

Then, the winding of the can lid 10 and the can body 20 thus configured is performed as follows.
As shown in FIG. 2A, the shoulder portion 14 and the curl portion 15 of the can lid 10 are placed on the flange portion 22 of the can body 20 mounted on a lifter (not shown), and the chuck 31 is fitted to the can lid 10 from above. In the state where the can body 20 and the can lid 10 are sandwiched between the chuck 31 and the lifter, the seaming roll 32 is approached from the outside in the radial direction so that the curled portion 15 of the can lid 10 and the can The flange portion 22 of the barrel 20 is curled integrally from the outside, and the curled portion 15 of the can lid 10 is wound around the outside of the flange portion 22 of the can barrel 20 so as to be entangled and folded. A double winding in which the compound 30 is interposed between the can body 20 and the can lid 10 in a compressed state as shown in FIG. Fastening portion 40 is configured It is.

The double tightening portion 40 is shown enlarged in FIG.
In the can body 20, the flange portion 22 is crushed by tightening so that the body hook 24, which is folded back radially outward from the upper end of the neck portion 21, extends almost radially outward of the neck portion 21 along the axial direction of the can. Has been placed.
In the can lid 10, a portion from the panel portion 11 to the chuck wall 13 enters the inside of the neck portion 21. And the shoulder part 14 and the curl part 15 are shape | molded by winding from the upper end of the chuck wall 13, and the seaming panel 42 which covers the turned-up part of the body hook 24 continues via the seaming panel radius 41, A seaming wall 44 extending downward from the outer peripheral edge of the seaming panel 42 via the seaming wall radius 43 is disposed radially outward of the body hook 24, and the cover hook radius 45 extends from the lower end edge of the seaming wall 44. A continuous cover hook 46 is interposed between the body hook 24 and the can body 20 from below and extends upward. The compound 30 applied to the inner surface of the curled portion 15 of the can lid 10 is interposed between the can body 20 and the can body 20 in a compressed state, so that the can body 20 and the can lid 10 can be provided. Is in a sealed state. In the double winding portion 40, as shown in FIGS. 2 (b) and 4, clearance portions C1 and C2 are formed at two upper and lower portions between the can lid 10 and the can body 20, and a lower clearance portion is formed. The surplus of the compound 30 filled in C1 is stored in the upper clearance portion C2.

In such a can lid 10, a sufficient thickness can be secured by using a thin lid member having a plate thickness of 0.230 mm or less.
In this case, the curvature radius R1 of the first curved portion 56b of the cover hook portion 56 is formed to be the same as or larger than the curvature radius R2 of the second curved portion 56c, so that the first curved portion 56b is bent. Since the rigidity can be lowered, the cover hook portion 56 can be reliably crushed and the sealing performance can be improved.

  When the radius of curvature R1 of the first curved portion 56b is smaller than the radius of curvature R2 of the second curved portion 56c, the bending rigidity of the first curved portion 56b is increased, and the radius of curvature R2 of the second curved portion 56c is 0.6 mm. If it is less than this, the bending rigidity of the second bending portion 56c becomes high, and it becomes difficult to crush the cover hook portion 56 to form a straight line, so that the sealing performance may be impaired. Further, when the radius of curvature R2 of the second curved portion 56c is larger than 1.1 mm, or when the radius of curvature R1 of the first curved portion 56b is larger than 1.4 mm, the cover hook portion 56 is Since the tip portion strongly hits the body portion of the can body 20 and proper winding cannot be performed, the sealing performance may be impaired.

  When the radius of curvature R3 of the cover hook radius portion 55 is smaller than 1.2 mm, the cover hook portion tip is engulfed, the compound 30 of the upper clearance portion C2 is pushed out, and the compound 30 may protrude. Moreover, when curvature radius R3 is larger than 2.1 mm, the shape freezing property after winding will deteriorate, there exists a possibility that the lower part of the double winding part 40 may open, and sealing performance may fall.

Next, examples will be described in comparison with comparative examples.
An aluminum alloy having a base plate thickness of 0.270 mm was formed as the can body, and an aluminum alloy having a base plate thickness of 0.220 mm was formed as the can lid. In that case, the 1st curved part and 2nd curved part of the cover hook part of each can lid, and the cover hook radius part were shape | molded on the conditions shown in Table 1, and the can lid from which a shape differs was produced. For the shape measurement of the cover hook portion and the cover hook radius portion, the shape of the curl portion of each can lid was measured three times with a contact-type shape measuring machine. The cover hook portion and the cover hook radius portion are tightened by winding a can lid around the can body, measuring a plurality of cover hook dimensions indicated by CH in FIG. 4, and using the average value of the measured values. In the previous can lid, the position corresponding to the cover hook dimension CH was determined from the end of the curled portion, and the index was determined.

The cover hook portion was divided into two equal parts, excluding 0.2 mm from the tip, and the portion closer to the end was defined as the first curved portion and the remaining portion was defined as the second curved portion. In measuring the radius of curvature R2 of the second curved portion, select a total of three points, two points close to both ends of the second curved portion and one point located substantially in the center, and determine the radius of curvature of the arc formed by them. Asked. The curvature radius was similarly determined for the curvature radius R1 of the first curved portion and the curvature radius R3 of the cover hook radius portion.
Five samples were prepared for each sample, and Table 1 shows the average value of the five measurement results.

Next, the can body was filled with a content liquid having a gas volume of 2.7, and the can lid was wound up to produce a beverage can, and an impact test was performed on each beverage can.
For the impact test, an impact tester shown in FIG. 5 was used. The impact testing machine 60 includes a table 61 for fixing the beverage can 70 at an angle, and a weight 62 dropped on the double winding portion 40 of the beverage can 70 fixed on the table 61. The weight 62 is formed by a swingable bar and is arranged so as to be substantially horizontal when it comes into contact with the double winding tightening portion 40 of the beverage can 70 on the table 61. It was allowed to fall freely from an angle of ° and collided with the double wrapping portion 40 of the beverage can 70 at a position with a rotation radius of 200 mm. Then, immediately after the impact test, it was inspected whether leakage occurred. As for the presence or absence of leakage, if there was a leakage that was reduced by more than a predetermined weight relative to the weight of the beverage can before the impact test, and if there was leakage in any one of the 5 cans, leakage occurred. When there was not, it was written as “none”.

  As can be seen from the results in Table 1, the radius of curvature R2 at the second curved portion of the cover hook portion is 0.6 mm to 1.1 mm, and the radius of curvature R1 at the first curved portion is the radius of curvature R2 of the second curved portion. Using a thin cover material by forming the radius of curvature R3 of the cover hook radius portion to be 1.2 mm or more and 2.1 mm or less, while being the same or larger and 1.4 mm or less. Can also ensure sealing performance.

  In addition, this invention is not limited to the said embodiment, A various change can be added in the range which does not deviate from the meaning of this invention.

10 Can lid (can lid for double winding)
DESCRIPTION OF SYMBOLS 11 Panel part 12 Counter sink 13 Chuck wall 14 Shoulder part 15 Curl part 20 Can trunk 21 Neck part 22 Flange part 24 Body hook 30 Compound 31 Chuck 32 Seaming roll 40 Double winding part 41 Seaming panel radius 42 Seaming panel 43 Seaming wall radius 44 Seaming wall 45 Cover hook radius 46 Cover hook 54 Seaming wall portion 55 Cover hook radius portion 56 Cover hook portion 56a Straight portion 56b First bending portion 56c Second bending portion 60 Impact testing machine 61 units 62 Weight 70 beverage cans

Claims (1)

A radius of the body hook is formed between a body hook formed by molding an aluminum plate having a thickness of 0.210 mm or more and 0.230 mm or less and folded back at the upper end of the cylindrical can body and the neck of the can body. A double-clamping can lid in which a continuous cover hook enters from the lower end of the seaming wall on the outer side through a cover hook radius and is double-clamped. A chuck wall provided on the outer edge portion of the chuck so as to continuously extend upward via a counter sink, and expands radially outward from the upper portion of the chuck wall, and then is folded downward to extend radially inward. A shoulder portion covering the open end of the can body, and a curl portion formed by folding back the outer peripheral edge portion downward and radially from the shoulder portion. The cover portion is formed to have a cover hook radius portion, a cover hook radius portion corresponding to a portion constituting the cover hook, and a cover hook portion when wound on the can body, and the cover hook The portion is located between the straight portion within a range of 0.2 mm from the tip, the first curved portion located on the tip side excluding the straight portion, and the first curved portion and the cover hook radius portion. And a radius of curvature of the outer peripheral surface of the second curved portion is 0.6 mm to 1.1 mm, and a radius of curvature of the outer peripheral surface of the first curved portion is the second curved portion. larger Ri by the radius of curvature of the outer peripheral surface of the curved portion, and is formed into a 1.4mm or less, the radius of curvature of the outer peripheral surface of the cover hook radius portion is formed on 1.2mm or 2.1mm or less Double characterized by Can lid for tightening.

Images