JP6576047B2 - Can lid - Google Patents

Description

  The present invention relates to a can lid that is wound around a metal can body that is filled with contents such as beverages.

  2. Description of the Related Art As a can used as a container for beverages or the like, a two-piece can in which a can lid is double-wrapped at an opening of a bottomed cylindrical can body is often used. In order to increase the pressure-resistant strength of the can lid, the width of the counter sink part is reduced, the diameter of the central panel part inside is reduced, or the peripheral wall part into which the chuck member, which is a tool for tightening, is fitted Various proposals have been made such as devising the shape of the (chuck wall).

Patent Document 1 includes a central panel portion, a counter sink portion (dish groove bead), an inclined chuck wall portion, and a winding portion, and strains along a partial arc of the counter sink portion or the chuck wall portion. A can lid provided with a control structure for the purpose of suppressing or preventing the concentration of water is disclosed. As its control structure,
A. Increase the radial position of the outer wall of the counter sink.
B. A recess is arranged at a position substantially in the middle of the chuck wall portion or above the chuck wall portion so as to be positioned at the base of the tightening portion when being wound around the can body.
C. Press the shoulder part inside or outside the counter sink part.
D. A shelf is provided on the outer wall of the counter sink.
It is described.

  If such a can falls in a state where it is housed in a carton case during transportation, etc., the height of the can may fall horizontally in the carton case. It is deformed into an ellipse so as to be crushed in the radial direction. In Patent Document 1, it is described that the panel portion is pushed outward by the internal pressure at that time, and the “projection” is broken, the force is concentrated on one point, and a pinhole may be generated at the tip of the “beak”. Has been. This “beak” is called a squeeze, but in the can lid described in Patent Document 1, by providing the control structure as described above, the force does not concentrate on one point and a gentle squeeze is formed. By doing so, it is described that the cornering is not accompanied by pinholes or breakage. In other words, even if the can is exposed to unintentional dropping or high pressure resistance, and even if it is squared out, leakage of contents due to pinholes and breakage can be prevented, so that it can be used as a product with reduced value Presumed to be the purpose.

JP 2006-514595 A

  However, the technique described in Patent Document 1 cannot prevent the occurrence of cornering itself, and if the can is dropped in a state of being packed in a carton case at the distribution stage, the can is deformed into an ellipse and the corner of the can lid is This will cause a drop in commercial value.

  The present invention has been made in view of such circumstances, and an object of the present invention is to provide a can lid that can reliably prevent cornering.

In the can lid of the present invention, a counter sink part forming an annular recess facing upward is continuously formed on the outer peripheral edge of the central panel part, and gradually as it goes upward from the outer peripheral edge of the counter sink part. A can in which a central peripheral wall portion that expands in diameter is formed, and a curl portion that is formed by folding the outer peripheral edge portion downward and radially inward through a shoulder portion that extends radially outward from the central peripheral wall portion. In the lid, the shoulder portion is curvedly formed in an arc shape that is convex upward and radially inward, and the central peripheral wall portion is a first curved portion that is convex inward in the radial direction; A second curved portion that is convex outward in the radial direction is formed in order from the outer peripheral edge of the counter sink portion to the inner peripheral edge of the shoulder portion. direction And elliptic deformation preventing mechanism is formed over the entire periphery, the elliptic deformation preventing mechanism is a thin reinforced portion formed by compressing a portion of the second curved portion in the thickness direction.

  When the whole carton case is dropped at the distribution stage, the can body deforms into an elliptical shape by the impact, and the can lid also tries to deform into an elliptical shape following the impact, but the elliptical deformation prevention mechanism is formed over the entire circumference. Therefore, the elliptical deformation of the can lid is prevented, and the occurrence of cornering can be prevented. In this case, the can lid is wound around the can body from the shoulder portion to the curl portion, and since the ellipse deformation preventing mechanism is formed in the second curved portion continuous from the shoulder portion, the position is close to the winding portion. By restraining the winding portion, it is possible to reliably prevent deformation near the can lid and the winding portion.

In addition, the thin-walled reinforcing portion is compressed in the plate thickness direction and has high strength, and has a high elliptical deformation preventing function, so that deformation can be reliably prevented.
The thickness of the thin reinforcing portion is 95% to 99% of the thickness of the portion other than the thin reinforcing portion, and the width is preferably 0.5 mm to 5.0 mm at the open end.

In the can lid of the present invention, the ellipse deformation prevention mechanism may be disposed at an intermediate position in the bending direction of the second bending portion.
When tightening the can lid around the can body, a tool (chuck member) for tightening is fitted into the can lid, but the vicinity of the central portion of the second bending portion in the bending direction is in contact with the chuck member. By forming an ellipse deformation prevention mechanism in this portion, interference with the chuck member can be prevented and a good tightening state can be obtained.

  In the can lid of the present invention, the ellipse deformation preventing mechanism may be formed in a concave groove shape toward the outer surface. If the ellipse deformation preventing mechanism has a concave groove shape toward the outer surface, even if it comes into contact with the chuck member, the tightening operation is not hindered.

In the can lid of the present invention, the ellipse deformation prevention mechanism may be formed in a concave groove shape toward the inner surface.
In this case, if the outer surface is formed so as to be flush with other portions without being deformed, it is not apparent from the appearance that the ellipse deformation preventing mechanism is formed, and the design is not impaired. In addition, the elliptical deformation prevention mechanism hardly interferes with the chuck member.

  According to the present invention, since the ellipse deformation prevention mechanism is formed along the circumferential direction in the second curved portion, the deformation is prevented even when the carton case is dropped, and the occurrence of leakage or squaring is reliably prevented. can do.

It is a longitudinal section showing one embodiment of a can lid concerning the present invention, and shows the state piled up on the flange part of a can body. It is an enlarged view of the principal part of the can lid of FIG. It is a longitudinal cross-sectional view which shows the state in the middle of winding from the state shown in FIG. It is a longitudinal cross-sectional view which shows the final stage of winding from the state shown in FIG. It is a longitudinal cross-sectional view which shows the state after winding the can lid of FIG. 1 around the can body. It is a front view which shows the example of a winding apparatus. It is an enlarged view of the principal part similar to FIG. 2 which shows other embodiment of this invention. It is an enlarged view of the principal part similar to FIG. 2 which shows other embodiment of this invention. It is a schematic diagram which shows a drop test method.

Hereinafter, an embodiment of a can lid according to the present invention will be described with reference to the drawings.
As shown in FIGS. 1 and 2, the can lid 1 is arranged in a disc shape at a central portion thereof, and a central panel portion 2 provided with a tab (not shown) for opening, and a central panel portion 2. A countersink part 4 which is continuous from the outer peripheral edge and forms an annular recess 3 facing upward; a central peripheral wall part 5 which is continuous while gradually increasing in diameter from the outer peripheral edge of the countersink part 4 upward; and a central peripheral wall A curled portion 7 is formed by folding the outer peripheral edge downward and radially inward via a shoulder portion 6 that extends outward from the portion 5 in the radial direction.

  The counter sink part 4 is formed by an inner wall part 11 connected to the central panel part, a folded part 12 continuing to the lower edge of the inner wall part 11, and an outer wall part 13 continuing to the outer peripheral edge of the folded part 12. Is done. The folded portion 12 may be formed by a plurality of arcs or a single arc in the longitudinal section thereof.

  The central peripheral wall portion 5 includes a first curved portion 15 that is continuous with the upper end edge of the outer wall portion 13 of the counter sink portion 4 and is curved so as to protrude radially inward, and an upper end edge of the first curved portion 15. And the second curved portion 16 curved so as to be convex outward in the radial direction, and the continuous shape of the first curved portion 15 and the second curved portion 16 as a whole Is shaped to expand upward. The radius of curvature of the first curved portion 15 and the second curved portion 16 is an aluminum alloy plate in which the nominal diameter of the can lid 1 is 204 and the original plate thickness before forming into the can lid 1 is 0.205 mm to 0.225 mm. Is used, the radius on the outer surface of the can lid 1 is 1.2 mm to 4.0 mm for the first curved portion 15 and 0.6 mm to 3.0 mm for the second curved portion 16. And the thin reinforcement | strengthening part 21 which compresses a part of plate | board thickness and thins is formed in this 2nd bending part 16 as an elliptical deformation prevention mechanism along the circumferential direction. Details of the thin wall reinforcing portion 21 will be described later.

The shoulder portion 6 is continuous with the upper end edge (outer peripheral edge) of the second curved portion 16 of the central peripheral wall portion 5 and expands radially outward while curving so as to be convex upward. . In this case, the second curved portion 16 of the central peripheral wall portion 5 is curved in a state in which its inner peripheral surface (outer surface as the can lid 1) is directed obliquely upward. Accordingly, the diameter of the shoulder portion 6 that continues to the second curved portion 16 is also increased from the bottom to the top.
The curled portion 7 is continuous with the outer peripheral edge of the shoulder portion 6 and extends outward in the radial direction, and the outer peripheral edge is folded downward and radially inward. Although not shown, a compound is applied to the inner surface of the curled portion 7.

  The thin-walled reinforcing portion (elliptical deformation prevention mechanism) 21 will be described in detail. The thin-walled reinforcing portion 21 is formed over the entire circumference of the can lid 1, and when the can lid 1 is molded, for example, as shown in FIG. By using the molds 51 and 52 indicated by the two-dot chain line, a part of the plate thickness is pressed by coining, and this is crushed and formed by the remaining plate thickness portion in which the concave groove 22 is formed. It will be. In the example shown in FIG. 1 and FIG. 2, the concave groove 22 is formed on the entire outer periphery of the can lid 1 by being pressed from the outer surface side to the intermediate position in the bending direction of the second bending portion 16. The opposite surface (the inner surface of the can lid 1) is formed flush with the surface of the other part. In this case, the thickness t of the thin-walled reinforcing portion 21 is 0.205 mm to 0.225 mm while the plate thickness of the portion other than the thin-walled reinforcing portion 21 (original plate thickness before forming the can lid) is 0.205 mm to 0.225 mm. The thickness is preferably 95% to 99% of the plate thickness, and the width W is preferably 0.5 mm to 5.0 mm at the open end of the groove 22.

On the other hand, in the can body 31 around which the can lid 1 is wound, a radially outward flange portion 35 is continuously connected to the upper end of the neck portion 33 whose diameter is reduced from the bottomed cylindrical body portion 32 via a bent portion 34. Thus, the shape is formed.
When the can lid 3 is put on the can body 31, the inner concave surface of the shoulder portion 6 of the can lid 1 is disposed so as to face the bent portion 34 of the can body 31, and the shoulder portion is disposed on the upper surface of the flange portion 35. The back surface from 6 to the curled portion 7 is arranged to face each other.

  When the can lid 1 is wound around the can body 31, as shown in FIG. 6, the chuck member 41 is fitted on the surface of the can lid 1 while pressing the can lid 1 covered on the can body 31 from above. Two winding rolls 43 and 44 approach the can body 31 and the can lid 1 that are rotated between the chuck member 41 and the lifter 42 that supports the bottom of the can body 31 from the radially outward position. Thus, the winding part 25 is formed. FIG. 3 shows a state where molding is performed by the first winding roll 43. After the molding, the second winding roll 44 is molded as shown in FIG. Meanwhile, the chuck member 41 remains fitted in the can lid 1.

  In the chuck member 41, a base metal part 45 that supports a pressing force applied inward in the radial direction applied from the winding rolls 43 and 44 at the time of winding is supported inside the shoulder part 6 of the can lid 1 outward in the radial direction. A curved taper-shaped portion 46 that is formed toward the bottom and faces the inner peripheral surface of the central peripheral wall portion 5 of the can lid 1 continuously extends downward from the base metal portion 45. An annular projecting portion 47 that fits into the counter sink portion 4 is formed below the counter sink portion 4. The curved tapered portion 46 has a convex curved surface 48 that faces the inner circumferential surface of the second curved portion 16 of the can lid 1 and a concave curved surface 49 that faces the inner circumferential surface of the first curved portion 15. Due to the continuous shape of the convex curved surface 48 and the concave curved surface 49, the overall shape is such that the diameter gradually decreases from the top to the bottom.

Further, in a state where the annular protrusion 47 is fitted to the counter sink portion 4, the outer surfaces from the base metal portion 45 to the convex curved surface 48 and the concave curved surface 49 of the curved tapered portion 46 are shown in FIGS. As shown in FIG. 4, a slight gap is formed between the corresponding shoulder portion 6 of the can lid 1 and the inner surfaces of both curved portions 16 and 15 of the central peripheral wall portion 5.
In this embodiment, the thin-walled reinforcing portion 21 described above is formed with the concave groove 22 on the outer surface of the can lid 1, so that even when the chuck member 41 is fitted during winding, it interferes with the chuck member 41. This makes it possible to perform good winding tightening.

  Then, as shown in FIG. 5, in the state where the can lid 1 is wound around the can body 31, the thinned reinforcing portion 21 is formed on the second curved portion 16 of the central peripheral wall portion 5 of the can lid 1 over the entire circumference in the circumferential direction. Therefore, even when the carton case is dropped at the distribution stage, it is difficult to deform. In particular, since the thinned reinforcing portion 21 is formed in the second curved portion 16 close to the tightening portion 25, deformation near the can lid 1 and the tightening portion 25 can be reliably prevented. In the can lid described in Patent Document 1 described above, it is described that there is an effect of suppressing a “beak” (sharp cornering) in which a force is concentrated on one point when a can falls and a pinhole may be generated. However, it is impossible to control the can itself deforming into an ellipse. In the case of the can lid 1 of the present embodiment, the thin-walled reinforcing portion 21 restrains the vicinity of the can lid 1 and the tightening portion 25 and can prevent the can itself from being deformed into an ellipse, and the occurrence of cornering is caused. Can be reliably prevented.

In the above-described embodiment, the thin reinforcing portion 21 that is an ellipse deformation preventing mechanism is formed so that the concave groove 22 is formed on the outer surface side of the can lid 1. However, as in the can lid 61 shown in FIG. It is good also as a thin-wall reinforcement | strengthening part (elliptical deformation prevention mechanism) 63 by shape | molding so that the ditch | groove 62 may be formed in the inner surface side of the lid | cover 61. FIG. Also in this case, the plate thickness t of the thin wall reinforced portion 63 is preferably 95% to 99% of the plate thickness of the portion other than the thin wall reinforced portion 62 (original plate thickness before forming the can lid 61), and the width W Is preferably 0.5 mm to 5.0 mm at the open end of the groove 62.
In the case where the thin reinforcing portion 63 is molded so that the concave groove 62 is formed on the inner surface side of the can lid 61, if the outer surface side of the can lid 61 is molded flush with other portions, Since it is not known that the thin-walled reinforced portion 63 is formed, the design as the can lid 61 is not impaired.

  Moreover, you may shape | mold a thin reinforcement | strengthening part so that a groove may be formed in either one of the inner surface or the outer surface of a can lid, and a protrusion may be formed in the other. The can lid 65 shown in FIG. 8 is an example in which a thin-walled reinforcing portion (elliptical deformation prevention mechanism) 68 is provided so that a concave groove 66 is formed on the inner surface side and a convex strip 67 is formed on the outer surface side. Also in this case, it is preferable that the plate | board thickness which comprises the bottom part of the ditch | groove 66 is 95%-99% of the plate | board thickness (original plate | board thickness before shaping | molding of a can lid) of the other part of a can lid, 0.5 mm to 5.0 mm is preferable at the opening end of the groove. Further, as described above, the protruding height of the ridge is set so as to be within a range of a gap generated between the chuck member and the can lid when being wound around the can body.

Next, a test was conducted to confirm the effect of the present invention.
A can lid (referred to as can lid A) in which a thin-walled reinforcing portion is formed so that a concave groove is formed on the outer surface using an aluminum alloy plate having a base plate thickness of 0.215 mm, and a can having no thin-walled reinforcing portion A lid (referred to as can lid B) was prepared. For comparison, an aluminum alloy plate having a base plate thickness of 0.235 mm was also used to produce a can lid (referred to as can lid C) that does not have a thin-walled reinforcing portion. As for the overall shape of these can lids, the overall shape other than the thin-walled reinforcing portion is as shown in FIG.

The can body is filled with 500 ml of carbonated water having a pressure of 2.0 kg / cm ² at room temperature as the contents, and the can lid is wound, and four rows of cans 72 are placed in a rectangular parallelepiped carton case 71 as shown in FIG. A total of 24 cans of x6 cans are accommodated and dropped onto the iron plate 73 with the side surface on the short side of the carton case 71 facing down (the can 72 is dropped with the height direction of the can 72 horizontally) The relationship between the drop height H and the number of cans with cornering was investigated.
The results are shown in Table 1. In Table 1, “good” is the case where there was no canned corner, and the numbers show the number of cans where the squared. In the test, the drop height was gradually increased, and the test was completed when even one can squared out in each can lid.

  As can be seen from the results in Table 1, the can lid A formed with the thin-walled reinforced portion is less prone to cornering than the can lid B without the thin-walled reinforced portion, and the can lid C formed of a thick aluminum alloy plate. Has the same pressure resistance. Therefore, the can lid A in which the thinned portion is formed can reduce the thickness of the aluminum alloy plate and can reduce the cost.

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.
As an example of the ellipse deformation prevention mechanism, an example in which the thin-walled reinforced portion is formed by compressing in the plate thickness direction is shown.

DESCRIPTION OF SYMBOLS 1 Can lid 2 Central panel part 3 Annular recessed part 4 Counter sink part 5 Central peripheral wall part 6 Shoulder part 7 Curled part 11 Inner side wall part 12 Folding part 13 Outer side wall part 15 First curved part 16 Second curved part 21 Thin reinforcement part ( Elliptical deformation prevention mechanism)
22 Groove 25 Winding part 31 Can body 32 Body part 33 Neck part 34 Bending part 35 Flange part 41 Chuck member 42 Lifter 43, 44 Winding roll 45 Base part 46 Curved taper part 47 Annular protrusion part 48 Convex curve Part 49 Concave curved part 51, 52 Mold 61 Can lid 62 Concave groove 63 Thin wall reinforcement part (elliptical deformation prevention mechanism)
65 Can lid 66 Concave groove 67 Convex line 68 Thin wall reinforcement part (elliptical deformation prevention mechanism)

Claims (5)

A counter sink part that forms an annular recess facing upward is continuously formed on the outer peripheral edge of the central panel part, and a central peripheral wall part that gradually increases in diameter from the outer peripheral edge of the counter sink part upwards. In the can lid, which is formed and continuously formed with a curled portion formed by folding the outer peripheral edge downward and radially inward through a shoulder portion extending radially outward from the central peripheral wall portion, the shoulder portion is The central peripheral wall portion is curved in an arc shape that is convex upward and radially inward, and the central peripheral wall portion is convex toward the radially inward direction and radially outward. A convex second curved portion is formed in order from the outer peripheral edge of the counter sink portion to the inner peripheral edge of the shoulder portion, and part of the curved direction of the second curved portion extends over the entire circumference in the circumferential direction. Circular deformation preventing mechanism are formed, the elliptic deformation preventing mechanism can lid characterized in that a portion of the second curved portion which is thin reinforced portion formed by compressing in the thickness direction. The thickness of the thin-walled reinforcing portion is 95% to 99% of the plate thickness of the portion other than the thin-walled reinforcing portion, and the width is 0.5 mm to 5.0 mm at the open end. The described can lid. The elliptical deformation preventing mechanism according to claim 1 or 2, wherein the can lid, characterized in that it is arranged in an intermediate position of the bending direction of the second curved portion. The can lid according to any one of claims 1 to 3, wherein the ellipse deformation preventing mechanism is formed in a concave groove shape toward an outer surface. The can lid according to any one of claims 1 to 3, wherein the ellipse deformation prevention mechanism is formed in a concave groove shape toward the inner surface.

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