JP5663232B2 - Can lid - Google Patents

Description

  The present invention relates to a can lid that is wound around an open end of a can body.

As a can lid of a beverage can, as shown in Patent Document 1, a steion tab type that can open a drinking mouth with a tab attached to a can lid body is known.
The can lid equipped with this tab has a tab attached by a rivet. By pulling up the lifting part of the tab, the vicinity of the rivet becomes a fulcrum, and the tab nose (the tip of the tab) acts as an action point. The opening piece surrounded by the score is pressed and immersed to break the score, and the opening piece is opened. At this time, the score is separated from the starting end portion and the terminal end portion, 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 and the opening property is poor. Become. Therefore, in order to obtain sufficient openness, it is conceivable to increase the cut depth of the score and reduce the remaining score thickness. In that case, however, the physical strength of the score decreases, and problems such as cracks occur. Could occur.

  Therefore, in Patent Document 1, the position of the rivet is eccentric to the opposite side of the opening piece with respect to the center of the can lid body, the tip of the opening piece is brought close to the peripheral edge of the can lid body, or these By adopting both, it is proposed that the aspect ratio of the opening piece becomes a predetermined ratio, thereby forming the opening piece in a wide mouth without impairing the openability and physical strength. Yes.

JP 2009-96493 A

  However, as in Patent Document 1, when the position of the rivet is decentered, or when the tip of the opening piece is brought close to the peripheral edge of the can lid body, the mold must be remodeled or significantly modified. It was expensive and not efficient.

  This invention is made | formed in view of such a situation, and provides the can lid | cover which can ensure suitable can openability with a simple structure.

The can lid of the present invention includes a rivet formed to project from the center of the upper surface of the can lid main body, an opening piece defined by a score leaving a hinge portion with the can lid main body, and the opening piece A tab attached to the rivet with one end overlapped, and pulling the other end of the tab upward, the one end presses the opening piece downward to break the score, and the opening piece A can lid that bends into the interior of the can lid body at the hinge portion and opens,
When the line passing through the center of the rivet and parallel to the longitudinal direction of the tab is a reference line, the opening piece is formed such that the maximum width in the direction perpendicular to the reference line is larger than the length on the reference line, The center of the maximum width is arranged shifted to the hinge part side from the reference line,
The tab has one end formed in an arc shape, and the center of the rivet hole into which the rivet is inserted is closer to the one end than the center of the arc forming the one end, and the hinge portion It is formed by being shifted to the opposite side.

  When the tab is raised to open the can, the middle part of the score near the rivet breaks first (pop operation). Then, the breakage progresses toward the starting end direction of the score, and at the same time, the breakage advances so as to go around the opening piece toward the end direction of the score in the opposite direction (tier operation), and the opening piece is bent at the hinge portion. The can is opened by completely entering the inside of the can lid. In such a can opening process, as the other end of the tab is pulled upward, the position where the one end of the tab contacts the opening piece rotates little by little along the arc shape of the one end. To move.

In the can lid of the present invention, since the rivet hole is close to the one end side of the tab, the breaking force (pop value) at the initial stage of opening the can can be reduced, and the can can be opened with a relatively small force. .
In addition, in the case of a wide-mouthed score in which the maximum width of the opening piece is expanded, the distance from one end of the tab to the score becomes longer as the tier operation progresses, and the direction of the pressing force transmitted by the tab and the opening piece are defined. Since the deviation from the progressing direction of the score break is gradually increased, there is a case where the can is not fully opened but a half-open can. However, in this can lid, the rivet hole of the tab is arranged so as to be shifted from the center of the arc forming one end of the tab to the side opposite to the hinge part side in accordance with the arrangement of the opening piece. Therefore, the contact position between one end of the tab and the opening piece can be brought close to the breaking position of the score to make an ideal arrangement, and the pressing force of the tab can be effectively transmitted to improve the openability. Can do.

  Furthermore, it is possible to respond by changing the arrangement of the rivet holes without significantly changing the overall shape of the tab, so that the tab can be produced with a simple configuration using existing equipment, and it is efficient. It is.

In the can lid of the present invention, the opening piece has a maximum width of 18 mm to 26 mm and a maximum length of 16 mm to 24 mm, and the tab has a total length of 22 mm to 26 mm and a total width of 12 mm. Is set to 16 mm or less,
When a point closest to one end of the tab of the rivet hole is a reference point, a ratio of a length from the reference point to one end of the tab with respect to a length from the other end of the tab to the reference point is 0.25 or more and 0.30 or less.
The center of the rivet hole is formed such that the amount of deviation from the center of the arc to the reference line is set in a range of 0.2 mm or more and 0.5 mm or less on the side opposite to the hinge portion. Good.

  In this way, by setting the arrangement of the rivet holes, the contact position between the one end of the tab and the opening piece and the breaking position of the score are brought close to each other, and the pressing force is effectively transmitted to improve the openability. In addition, it is possible to produce a tab with a modified arrangement of rivet holes with a simple configuration using existing equipment.

  According to the present invention, with a relatively simple configuration of changing the arrangement of the rivet holes of the tab, it is possible to realize an ideal arrangement of the opening piece and the tab suitable for transmitting the pressing force of the tab. A suitable openability can be ensured.

It is a top view which shows the can lid of this embodiment. It is AA sectional drawing of the can lid shown in FIG. It is a principal part enlarged view explaining the relationship between the rivet hole of a tab, and an opening piece.

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 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 (the lower side of the rivet 3 in FIG. 1). A finger-hanging recess 6 is formed on the opposite side (the upper side of the rivet 3 in FIG. 1) through 3, and a pair of protrusions 7 called dimples are formed between the rivet 3 and the finger-holding recess 6. ing.
A concave panel deboss 10b is formed so as to extend in the longitudinal direction of the tab 2 so as to surround the opening piece 5, the finger hook concave portion 6, and the convex portion 7, and a panel is formed by the outer peripheral wall 10c constituting the panel deboss 10b. The rigidity of the entire portion 10a is increased.

As shown in FIG. 1, the score portion 4 includes a start end portion 41, a concave arc 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 hinge portion 45 that is a connection portion with the panel portion 10 a between the start end portion 41 and the end portion 44. The concave arc portion 42 is formed in a ring-shaped coined portion that is crushed by coining around the rivet 3.
The score portion 4 has a double structure including a main score 4a that is broken by pressing by the tab 2 to form the opening piece 5, and an auxiliary score 4b that is formed in parallel adjacent to the inside of the main score 4a. The main score 4a and the auxiliary score 4b are connected to each other at the start end portion 41 and the end end portion 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.

Further, when the opening piece 5 passes through the center of the rivet 3 and is parallel to the longitudinal direction of the tab 2 as a reference (reference line B), the maximum width W1 in the direction orthogonal to the reference line B is above the reference line B. The center C of the maximum width W1 is shifted from the reference line B toward the hinge portion 45 (ΔW1 shown in FIG. 3). The opening piece 5 is set so that the maximum width W1 is set to 18 mm or more and 26 mm or less, and the maximum length L1 is set to be smaller than the maximum width W1 in the range of 16 mm or more and 24 mm or less.
An inner bead 8 that protrudes along the score portion 4 is formed on the opening piece 5 to reinforce the opening piece 5.

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.
The one end portion 21 is formed in an arc shape, and a tongue portion 24 is formed by a U-shaped slot 24 a between the one end portion 21 and the lifting portion 22, and a rivet hole 25 is formed in the tongue portion 24. ing. The tab 2 is attached in a state where the rivet 3 is inserted into the rivet hole 25 and the lower surface of the tongue portion 24 is in contact with the surface of the panel deboss 10b.

The tab 2 is set to have a total length L2 of 22 mm to 26 mm and a total width W2 of 12 mm to 16 mm, and the center 25c of the rivet hole 25 of the tab 2 is from the center 20c of the arc forming the one end 21. Is also formed on the one end 21 side and shifted to the opposite side to the hinge portion 45 of the opening piece 5. In this case, assuming that the point closest to the one end 21 of the rivet hole 25 is a reference (reference point d), the length from the reference point d to the one end 21 with respect to the length L21 from the other end of the tab 2 to the reference point d. The ratio L22 (L22 / L21) is set to 0.25 or more and 0.30 or less. Further, the shift amount ΔW2 of the center 25c of the rivet hole 25 is set to 0.2 mm or more and 0.5 mm or less.
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.

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.
Further, the side surface 61 of the finger hooking recess 6 is provided continuously with a part of the outer peripheral wall 10c of the panel deboss 10b, and the bottom surface 62 is formed so as to be further depressed downward from the upper surface of the panel deboss 10b.

  Two protrusions 7 protrude from the upper surface of the panel deboss 10 b and are formed in the width direction of the tab 2 at intervals. And the outer edge part of the tab 2 is hooked on this pair of convex part 7, and the rotation movement of the tab 2 can be prevented now.

In the can lid 100 configured as described above, when the pulling portion 22 of the tab 2 is pulled upward, first, the rivet 3 is lifted upward with the one end portion 21 of the tab 2 on the opening piece 5 as a fulcrum. As a result, the rivet 3 side of the concave arc portion 42 is lifted upward in a state where the opening piece 5 side of the concave arc portion 42 of the main score 4a is pressed by the tab 2, and a shearing force acts on the concave arc portion 42 and breaks. (This is the 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 main score 4a is pushed into the can by the tab 2 while the main score. 4a sequentially breaks and opens so as to go around the opening piece 5 (after the pop operation is referred to as a tear operation).
At this time, as the pulling portion 22 of the tab 2 is pulled upward, the position where the one end portion 21 of the tab 2 and the opening piece 5 come into contact with each other is clockwise around the rivet 3 along the arc shape of the one end portion 21. Move to rotate little by little.

In the can lid 100 of the present embodiment, since the rivet hole 25 is close to the one end 21 side of the tab 2, the breaking force (pop value) at the initial stage of opening the can can be reduced, and the opening can be performed with a relatively small force. Can be can.
Further, the rivet hole 25 of the tab 2 is arranged so as to be shifted from the center 20c of the arc forming the one end 21 of the tab 2 to the opposite side of the opening piece 5 from the hinge portion 45 side according to the arrangement of the opening piece 5. Therefore, the contact position between the one end portion 21 of the tab 2 and the opening piece 5 can be brought close to the breaking position of the score portion 4 to achieve an ideal arrangement, and the pressing force of the tab 2 can be effectively transmitted. And can openability can be improved.
Furthermore, it is possible to respond by changing the arrangement of the rivet holes without significantly changing the overall shape of the tab, so that the tab can be produced with a simple configuration using existing equipment, and it is efficient. It is.

Next, with respect to the can lid 100 configured as described above, various can lids can be used under the conditions shown in the following Tables 1 to 3 where the rivet holes 25 of the tab 2 are located (Tables 1 to 3 are the same corresponding conditions). The can openability at the time of pop operation with a single can lid (initial can openability), the can openability at the tear operation (tear openability), and the can openability in the filled can (filled can openability) ) And confirmed.
“L22 / L21” in Tables 1 to 3 is the ratio of the length L22 from the reference point d to the one end 21 to the length L21 from the other end of the tab 2 to the reference point d shown in FIG. L21). Further, “ΔW2” corresponds to the shift amount ΔW2 of the center 25c of the rivet hole 25 shown in FIG. 3, and is opposite to the hinge part 45 from the arc center 20c of the one end 21 of the center 25c of the rivet hole 25. Indicates the amount of displacement to the side.
The tab 2 has a total length L2 of 25 mm and a total width W2 of 15.5 mm. In this tab 2, the ratio L22 / L21 is set to 0.300 to 0.310, and the shift amount ΔW2 is set to 0.0 mm. The center 25c of the rivet hole 25 is disposed at the center 20c of the arc of the one end 21 of the tab 2.

(Evaluation of initial openability)
Ten can lids of each condition were prepared for L22 / L21 and ΔW2, and the tab lifting portion was forcibly pulled up with these can lids fixed to confirm the can openability. In this case, a series of operations from the pop operation to the tier operation was continuously performed. However, the can openability during the pop operation and the can openability during the tier operation were separately displayed in Tables 1 and 2.
Table 1 shows the results of evaluating the initial can openability.
“◯” in Table 1 indicates that all the ten can lids broke the concave arc portion of the main score without any problem and were initially opened. “Δ” indicates that all ten can lids were initially opened, but the pop value was higher than that in the case of “◯”, indicating that a large force was required. “Tab break” means that the can was opened at the initial stage but the tip (one end) of the tab was broken. “Unopened can” indicates that there was a can lid in which the leading end of the tab was broken without breaking the main score.
Note that “tab break” and “unopened can” indicate that at least one of the can tabs of “tab break” and “unopened can” occurred.

  As shown in Table 1, when the ratio (L22 / L21) of the length L22 from the reference point d to the one end 21 with respect to the length L21 from the other end of the tab 2 to the reference point d is reduced, that is, a rivet hole Can be lowered to the one end portion side of the tab, the pop value can be lowered, and the initial can can be reliably opened. However, when the rivet hole was shifted to one end side, the load applied to the tip of the tab was large, and although the initial can opening was possible, the tab broke. Further, it was found that when the rivet hole displacement amount ΔW2 is shifted by a large amount of 0.6 mm, the pop value becomes high and the openability of the can deteriorates.

(Tear openability evaluation)
Table 2 shows the evaluation results of the opening performance of the tear operation after the initial opening. The remaining can lids were evaluated except for the can lids that were broken tabs or became unopened during the pop operation.
“◯” in Table 2 indicates that all can lids were broken and opened in the entire area of the main score. In addition, “half-open can” indicates that there was a can lid that could not be opened due to the breaking of the main score in the middle, indicating that at least one half-open can occurred. ing.

  As shown in Table 2, in the tear operation, it can be seen that when the ratio L22 / L21 is reduced and the shift amount ΔW2 is reduced, the can is half-opened. Therefore, in this case, the rivet hole is shifted from the center of the arc forming one end of the tab to one end and to the side opposite to the hinge portion of the opening piece, and arranged in a balanced manner. Good can openability can be obtained even in the tear operation.

(Filling can openability evaluation)
Using the sample can lid described above, a beverage can filled with the content liquid of gas volume 3.0 was prepared, and this beverage can was left in a constant temperature room at 40 ° C. for 24 hours, and then opened at 5 ° C. Then, the opened state was confirmed. Table 3 shows the results.
“◯” in Table 3 indicates that all ten can lids were broken and opened in the entire area of the main score. In addition, “half-open can” indicates that there was a can lid that could not be opened due to the breaking of the main score in the middle, indicating that at least one half-open can occurred. ing.

  As shown in Table 3, when the ratio L22 / L21 is set to 0.250 or more and 0.300 or less and the shift amount ΔW2 is set to 0.2 mm or more and 0.5 mm or less, a good can openability can be obtained. I understand that. This setting condition is included in the conditions under which good results were obtained in both the initial can openability evaluation and the tear openability evaluation described above. When a filling can is used, the pop value increases, so the rivet hole is shifted toward one end of the tab to displace the initial contact position between one end of the tab and the opening piece, thereby reducing the pop value. It turns out that it is effective. Also in this case, good can opening performance can be obtained by arranging the rivet holes on the opposite side of the hinge portion in a balanced manner so that a good tearing operation can be performed.

As described above, the rivet hole of the tab is shifted from the center of the arc that forms one end of the tab to the opposite side of the hinge portion side of the opening piece according to the arrangement of the opening piece. It is possible to achieve an ideal arrangement close to the breaking position of the main score that goes around the contact position between the one end portion and the opening piece, and to effectively transmit the pressing force of the tab and improve the can openability. it can.
In addition, it is possible to respond by changing the arrangement of the rivet holes without significantly changing the overall shape of the tab, so that the tab can be produced with a simple structure using existing equipment, which is efficient. It is.

  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 100 Can lid 1 Can lid main body 2 Tab 3 Rivet 4 Score part 4a Main score 4b Auxiliary score 5 Opening piece 6 Finger recessed part 7 Convex part 8 Inner bead 10a Panel part 10b Panel debossed 10c Outer peripheral wall 11 Corner part 12 Annular recessed part 13 Counter sink Part 14 Chuck wall part 15 Shoulder part 16 Shoulder curl part 21 One end part 22 Lifting part 23 Tab hole part 24 Tang part 25 Rivet hole 41 Start end part 42 Concave arc part 43 Intermediate part 44 Terminal part 45 Hinge part 61 Side face 62 Bottom face

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 leaving a hinge portion with the can lid body, and an end piece overlying the opening piece, the rivet A tab attached to the tab, and pulling up the other end of the tab upward, the one end presses the opening piece downward to break the score, and the opening piece is moved to the can by the hinge portion. A can lid that is folded and opened inside the lid body,
When the line passing through the center of the rivet and parallel to the longitudinal direction of the tab is a reference line, the opening piece is formed such that the maximum width in the direction perpendicular to the reference line is larger than the length on the reference line, The center of the maximum width is arranged shifted to the hinge part side from the reference line,
The tab has one end formed in an arc shape, and the center of the rivet hole into which the rivet is inserted is closer to the one end than the center of the arc forming the one end, and the hinge portion A can lid characterized by being formed to be shifted to the opposite side.   The opening piece has a maximum width of 18 mm to 26 mm, the maximum length is set to 16 mm to 24 mm, and the tab has a total length of 22 mm to 26 mm and a total width of 12 mm to 16 mm, When a point closest to one end of the tab of the rivet hole is a reference point, a ratio of a length from the reference point to one end of the tab with respect to a length from the other end of the tab to the reference point is The can lid according to claim 1, which is not less than 0.25 and not more than 0.30. The center of the rivet hole is formed such that a deviation amount from the center of the arc to the reference line is set in a range of 0.2 mm or more and 0.5 mm or less on the side opposite to the hinge portion. The can lid according to claim 1 or 2, characterized by the above.

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