JP2011255929A - Can lid and method of manufacturing tab of the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a can lid capable of opening a can with comparatively small force and ensuring suitable can openability, and to provide a method of manufacturing its tab.SOLUTION: In an end 21 of the tab 2, both-end edges 202 are separated via a notch 201 formed at a front end thereof, and these both-end edges 202 are folded back to the back surface side. As a result, a curled portion 26 is formed from the outer peripheral surface of the end 21 to the back surface, and in the back surface side of the front end of the end 21, notch edges 203 of both side edges 202 which is separated by the notch 201 project from the surface of the curled portion 26 toward a can lid body 1.

Description

  The present invention relates to a can lid wound around an open end of a can body and a method for manufacturing a tab used for the can lid.

As a can lid of a beverage can, as shown in Patent Document 1 and Patent Document 2, a steion tab type that can open a drinking mouth with a tab attached to a can lid body is known.
The can lid with this tab is attached to the tab with a rivet. By pulling up the finger hook of the tab, the vicinity of the rivet is bent and becomes a fulcrum, and the tab nose (the tip of the tab) acts as a working point. The opening piece surrounded by the score on the surface is pressed and immersed to break the score, thereby opening the opening piece. At this time, the panel surface is broken along the score shape, and the opening piece is pushed into the beverage can and opened without leaving the can lid.

By the way, in recent years, there is an increasing demand for improving the pouring property of contents. As a means for improving the pouring property, for example, the opening area of the opening piece is increased. However, if the opening area of the opening piece is increased, a large breaking force is required at the time of opening the can.
Therefore, in Patent Document 1, in order to reduce the breaking force at the time of opening the can, by extending both ends of the U-shaped tab cut portion provided around the rivet of the tab in the direction of the tip of the tab nose portion, It has been proposed to lower the initial can opening force by bringing the bent position (fulcrum) of the tab closer to the tip (operating point) of the tab nose portion which is the operating point of the can opening operation.
In addition, in Patent Document 2, a mountain-shaped bulge is provided at the edge of the quarter end of the tab nose that has been processed into a semicircular shape, and the score is completely up to the terminal. Proposals have been made for breaking the material.

JP 2001-48171 A JP 2006-56550 A

However, in the case of the tab of Patent Document 1, the initial opening force can be reduced by bringing the bent position of the tab closer to the tip of the tab nose portion, but the reduction is not sufficient.
Further, when a part of the edge of the tab nose portion is formed to be large as in Patent Document 2, the pressing force by the tab can be transmitted to the score terminal portion, but the opening force can be reduced during the opening operation. There are not enough measures taken.

  The present invention has been made in view of such circumstances, and can be opened with a relatively small force, and a can lid capable of ensuring a suitable openability and a tab used for the can lid. A manufacturing method is provided.

  The can lid of the present invention includes a rivet that protrudes from the center of the upper surface of the can lid body, an opening piece defined by a score, and a tab that is attached to the rivet with one end overlapped on the opening piece. A can lid for opening the opening piece by pulling the other end of the tab upward, the one end pressing the opening piece downward to break the score. The one end portion of the one end portion is separated from both side edge portions through a notch formed at the tip thereof, and the both side edge portions are folded back to the back surface side, whereby a curled portion is formed from the outer peripheral surface of the one end portion to the back surface. The cut end edges of both side edges separated by the notches protrude from the surface of the curl portion toward the can lid body on the back side of the tip of the one end.

In this can lid, the notched end edges of both side edges located at the tip of one end of the tab are provided so as to protrude from the surface of the curled portion of the tab toward the can lid main body. The protrusion can reduce the contact area between the opening piece and the tab when opening the can, and the notch edge abuts against the opening piece so that the contact point is stabilized, and the sliding between the opening piece and the tab is possible. Since the pressing force can be reliably transmitted, the breaking force (pop value) at the initial stage of opening the can can be reduced.
Furthermore, even in the tearing operation after the initial break, the notch edge protruding in the tab pressing direction bites into the opening piece and is fixed, so that the operating point is stable, and the sliding between the opening piece and the tab is stable. Can be reduced, the pressing force can be effectively transmitted, and the openability can be improved.

And the manufacturing method of the tab of this invention is a manufacturing method of the tab which cut out and shape | molded the metal plate, and was formed in the curl part from the outer peripheral surface to the back surface at one end part, Comprising: The front-end | tip of the said one end part in the said metal plate By forming a notch at a position corresponding to, and folding back both side edges that have been separated by cutting out through the notch to the back side, and abutting the notch edges of both side edges in the middle of the folding The butted portion of the cut-out edge forms the curled portion raised on the back surface side.
When the notch is formed smaller than the normal one and both side edges are folded back to the back side, the notched edges are butted together before the curled part is completely formed, and further folded in the butted state The butted portion is raised from the surface of the surrounding curled portion. In this case, the protrusion amount of the notch edge can be appropriately set by adjusting the notch shape.

The tab manufacturing method of the present invention is a tab manufacturing method in which a metal plate is cut out and formed, and a curled portion is formed on one end portion from the outer peripheral surface to the back surface, and the tip of the one end portion of the metal plate is formed. A notch is formed at a position corresponding to, and the notched end edges of both side edges that are separated by being cut out through the notches are raised, and then the both side edges are folded back to the back side to Further, the curled portion is formed such that the notched end edge protrudes toward the back surface side.
In this way, by curling up both side edges to the back side after raising the notch edge, a curled portion with the notch edge protruding can be formed. In this case, the amount of protrusion from the curled surface can be appropriately set by adjusting the rising height.

  According to the present invention, in particular, the breaking force at the initial stage of opening the can can be reduced and the can can be opened with a relatively small force, and a suitable opening property can be secured.

It is a top view which shows one Embodiment of the can lid of this invention. It is sectional drawing of the can lid shown in FIG. It is a plane part explaining a score part. It is a reverse view explaining a tab. It is AA sectional drawing shown in FIG. It is sectional drawing explaining the one end part of the tab in other embodiment, (a) is the state before a curl process, (b) is the state after a curl process.

Hereinafter, an embodiment of a can lid of the present invention will be described with reference to the drawings.
The can lid 100 of the present embodiment is a so-called stab tub type can lid used for beverage cans, and is composed of a can lid body 1 and a tab 2 as shown in FIG. The main body 1 and the tab 2 are each formed of pure aluminum or an aluminum alloy.

  As shown in FIGS. 1 and 2, the can lid main body 1 has a disk-shaped panel portion 10a disposed in the central portion thereof, and continues downward from the outer peripheral edge of the panel portion 10a via the corner portion 11. A counter sink portion 13 that forms a ring-shaped recess 12 facing the chuck, a chuck wall portion 14 that extends from the outer peripheral edge of the counter sink portion 13 while increasing in diameter upward, and a shoulder that extends from the outer peripheral edge of the chuck wall portion 14. It is composed of a portion 15 and a shoulder curl portion 16 continuous with the shoulder portion 15.

  As shown in FIG. 1, a rivet 3 is formed on the upper surface of the panel portion 10 a so as to protrude from the center portion of the panel portion 10 a (can lid main body 1). A tab 2 is attached to the rivet 3. Further, an opening piece 5 defined by the score portion 4 is formed in a portion extending in a specific radial direction from the rivet 3 on the upper surface of the panel portion 10a (on the left side of the rivet 3 in FIG. 1). A finger-hanging recess 6 is formed on the opposite side (the right side of the rivet 3 in FIG. 1), and a protrusion 7 called dimple is formed between the rivet 3 and the finger-holding recess 6. A concave panel deboss 10 b is formed so as to surround the opening piece 5, the finger-hanging concave portion 6, and the convex portion 7.

As shown in FIG. 3, the score portion 4 includes a start end portion 41, an arc-shaped portion 42 that is an arc-shaped initial fracture portion that substantially halves the rivet 3, a substantially elliptical intermediate portion 43, and a termination portion 44. The opening piece 5 is defined by leaving a part of the connection portion 45 to the panel portion 10 a between the start end portion 41 and the end portion 44. The arc-shaped portion 42 is formed in a ring-shaped coined portion that is crushed by coining around the rivet 3.
Moreover, the score part 4 is a double structure provided with the main score 4a which is fractured | ruptured by the press by the tab 2, and forms the opening piece 5, and the auxiliary score 4b formed in parallel adjacent to the inside of the main score 4a. The main score 4 a and the auxiliary score 4 b are connected to each other at the start end 41 and the end end 44 of the score portion 4.
The auxiliary score 4b is formed shallower than the adjacent main score 4a and is not broken by the pressing of the tab 2.

An inner bead 8 that protrudes along the score portion 4 is formed on the opening piece 5 to reinforce the opening piece 5.
When the pull-up recess 22 of the tab 2 is lifted, the finger-hanging recess 6 is arranged to facilitate the pull-up by placing a fingertip below the pull-up portion 22, and to the panel portion 10 a near the pull-down portion 22. Is formed.
Two protrusions 7 protrude from the panel deboss 10 b and are formed at intervals in the width direction of the tab 2. And the outer edge part of the tab 2 is hooked on the convex part 7, and the rotation movement of the tab 2 can be prevented now.

The tab 2 is formed flat by cutting out a metal plate such as aluminum, and is formed on the opposite side across the rivet 3 with the one end 21 disposed so as to overlap the opening piece 5. The other end part is provided with a lifting part 22, and the lifting part 22 is formed with a tab hole part 23 that opens in the thickness direction of the tab 2. A tongue portion 24 is formed by a U-shaped slot 24 a between the one end portion 21 and the lifting portion 22. A rivet hole 25 is formed in the tongue portion 24, and the rivet 3 is inserted into the rivet hole 25. Thus, the tab 2 is attached in a state where the lower surface of the tongue portion 24 is in contact with the surface of the panel deboss 10b.
The rivet 3 is formed by applying a coining process in which the periphery of the center of the panel portion 10a is pressed in a ring shape from above to project the center portion of the panel portion 10a upward.

Next, the one end 21 of the tab 2 will be described.
In FIG. 4, a two-dot chain line indicates the outer shape of the blank 200 before being punched, and a hatched portion indicates a portion that is folded back to become a curled portion.
As shown in FIG. 4, the one end 21 is separated from both side edges 202 through a notch 201 formed at the front end, and the both side edges 202 are folded back to the back surface side. A curled portion 26 is formed from the outer peripheral surface to the back surface, and the notch edge 203 of both side edge portions 202 separated by the notch 201 is butted against the back surface side of the tip of the one end portion 21. As shown in FIG. 5, the curl portion 26 is provided so as to protrude toward the can lid body 1.
The curled portion 26 is provided with at least a pair of recesses 28 with the butted portion 27 of the notch edge 203 interposed therebetween. The concave portion 28 avoids contact with the inner beat 8 provided on the opening piece 5 and reinforces the curled portion 26, so that the abutting portion 27 of the notched edge 203 is opened even if force is applied at the time of opening the can. It prevents it.

  In order to form such a tab 2, first, holes formed in the tab 2 such as the tab hole portion 23 are sequentially formed in the metal plate, and then the blank 200 of the tab 2 except for the connecting piece 204 having a required width. In the state where the blank 200 is connected with the connecting piece 204, the uneven shape is appropriately formed, the outer peripheral edge is subjected to curl forming, and finally the connecting piece 204 is cut to complete the tab 2. Let

In this case, as shown in FIG. 4, the blank 200 of the tab 2 is formed with a V-shaped notch 201 at a position corresponding to the tip of the one end 21, and then the outer shape of the blank 200 is cut out through the notch 201. Is formed. The notch 201 has a V-shaped opening angle smaller than that of the conventional one, and when the both side edges 202 separated by the notch 201 are folded back to the back side, both side edges 202 are in the middle of curling. When the notched end edges 203 of the notched edges 203 are brought into contact with each other and are curled to the end in this state, a curled portion 26 in which the butted portions 27 of the notched end edges 203 are raised on the back surface side is formed. The cut-out edge 203 is a cut edge of the metal plate, and is formed on one side of the plate thickness of the cut-out edge 203, that is, the inner peripheral edge of the curled portion 26 indicated by X in FIG. The notched edges 203 of each other are abutted, and the other side of the plate thickness, that is, the outer peripheral edge of the curled portion 26 indicated by Y in FIG. 5 is directed to the panel portion 10a of the can lid body 1. .
The amount of protrusion of the notch edge 203 from the curled portion 26 can be appropriately set by adjusting the notch shape.

  As shown in FIG. 6 (a), the notched edge 203 of the side edges 202 is raised in advance, and then the side edges 202 are folded back to the back side, as shown in FIG. 6 (b). Alternatively, the notched edge 203 in the raised state may be abutted to form the curled portion 26 protruding to the back surface side. In this case, most of the cutout edge 203 is directed to the panel portion 10a of the can lid body 1. By adjusting the rising height of the notch edge 203, the amount of protrusion from the surface of the curled portion 26 can be appropriately set.

In the can lid 100 configured as described above, when the lifting portion 22 of the tab 2 is lifted upward, first, a notch edge 203 protruding from the tip of the one end portion 21 of the tab 2 on the opening piece 5 serves as a fulcrum. The rivet 3 is lifted upward. At this time, the notch edge 203 can reduce the contact area with the opening piece 5, and the notch edge 203 abuts against the opening piece 5 and bites into the opening piece 5, so that the fulcrum is stabilized. The sliding force can be reduced and the pressing force can be reliably transmitted.
Thereby, in a state where the opening piece 5 side of the arc-shaped portion 42 of the main score 4 a is pressed by the tab 2, the rivet 3 side of the arc-shaped portion 42 is lifted upward, and shear force acts on the arc-shaped portion 42. Break (pop operation).

When the tab 2 is further lifted, the rivet 3 serves as a fulcrum, the action point becomes one end 21 of the tab 2, and the opening piece 5 surrounded by the score portion 4 is pushed into the can by the tab 2. 4 sequentially breaks and opens (tier operation).
Also at this time, since the cut-out edge 203 of the one end portion 21 bites into the opening piece 5 and is fixed, the action point is stabilized, the sliding between the opening piece 5 and the tab 2 is reduced, and the pressing force is reduced. Can be effectively transmitted, and can opening property can be improved.

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

DESCRIPTION OF SYMBOLS 1 Can lid main body 2 Tab 3 Rivet 4 Score part 4a Main score 4b Auxiliary score 5 Opening piece 6 Finger hook recessed part 7 Convex part 8 Inner bead 10a Panel part 10b Panel deboss 11 Corner part 12 Annular recessed part 13 Countersink part 14 Chuck wall part 15 Shoulder part 16 Shoulder curl part 21 One end part 22 Pull-up part 23 Tab hole part 24 Tang part 25 Rivet hole 26 Curl part 27 Butting part 28 Recessed part 41 Starting end part 42 Arc-shaped part 43 Intermediate part 44 End part 45 Connection part 100 Can lid 200 Blank 201 Notch 202 Both side edges 203 Notch edge 204 Connecting piece

Claims (3)

  A rivet formed to project from the center of the upper surface of the can lid body, an opening piece defined by a score, and a tab attached to the rivet with one end overlaid on the opening piece, By pulling the other end upward, the one end presses the opening piece downward to break the score, and the opening piece is opened. The one end of the tab is Both side edges are separated through a notch formed at the front end, and the both side edges are folded back to the back side, so that a curled part is formed from the outer peripheral surface of the one end to the back. A can lid characterized in that, on the back surface side of the tip, notched end edges of both side edges separated by the notch project from the surface of the curled portion toward the can lid body.   A method of manufacturing a tab in which a metal plate is cut out and formed, and a curled portion is formed at one end portion from the outer peripheral surface to the back surface, wherein a notch is formed at a position corresponding to the tip of the one end portion of the metal plate, The both side edges that have been separated by cutting through the notches are folded back to the back side, and the notched edges of the notched edges are brought into contact with each other in the middle of the folding, so that the butted part of the notched edges is on the back side. A method for manufacturing a tab, characterized in that the curled portion that is raised is formed. A method of manufacturing a tab in which a metal plate is cut out and formed, and a curled portion is formed at one end portion from the outer peripheral surface to the back surface, wherein a notch is formed at a position corresponding to the tip of the one end portion of the metal plate, After raising the notched end edges of both side edges that have been separated by cutting through the notches, the raised notched edge edges project to the back side by folding the both side edges back to the back side. A method for manufacturing a tab, comprising forming the curled portion.

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