JP6772038B2 - Can lid - Google Patents

Description

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

As a can lid for a beverage, as shown in Patent Document 1 and Patent Document 2, a stayion tab type that can open a drinking spout with the tab attached to the can lid body is known. In the can lid equipped with this tab, the tab is attached by a rivet, and by pulling up the pulling part of the tab, the vicinity of the rivet becomes a fulcrum, and the tab nose part (the tip of the tab) becomes a point of action on the panel surface. The opening (opening piece) surrounded by the score is pressed and immersed to break the score, and the opening is opened. At this time, since the start end and the end of the score are provided apart from each other, the opening is pushed into the can without being separated from the can lid to open the can.

By the way, in this type of can lid, in order to obtain good pouring property of the contents, it is possible to increase the opening area of the opening as described in, for example, Patent Document 1 or Patent Document 2. It is done.
In Patent Document 1, the main opening (first opening) defined by the main score (first score) and the area opposite to the main opening with the rivet sandwiched are projected on the upper surface of the can lid main body. A can lid in which a ventilation opening (second opening) defined by a sub-score (second score) is formed is described. Further, in Patent Document 1, the main opening of the can lid and the ventilation opening are connected via a bent portion, the other end of the tab is pulled up, the main score is broken, and the opening is opened. It is described that sometimes, by concentrating stress on the bent portion and breaking the bent portion, the ventilation opening is surely opened as the starting point at which the sub-score breaks the bent portion, and good pouring property is obtained. There is.

Further, in the can lid described in Patent Document 2, the opening formed in the can lid main body is defined by the first score and the third score, and the main opening (first) in which one end side of the tab overlaps. An opening) and a sub-opening (second opening) defined by a second score and a third score and formed in a region opposite the main opening with a rivet in between. , The first score and the second score are connected by the third score, and the main opening and the sub-opening are formed in the opposite region sandwiching the rivet. Then, in Patent Document 2, a large opening composed of a main opening and a sub-opening is formed in the can lid by breaking the score over the entire length to open the opening, and the sub-opening is inserted into the can. It is described that the contents are efficiently discharged from the main opening by the air that can flow freely.

Japanese Unexamined Patent Publication No. 2007-22541 Japanese Unexamined Patent Publication No. 2008-168923

As described in Patent Document 1 or Patent Document 2, by providing the second opening together with the first opening for pouring the contents to the outside, the contents can be poured out from the opening of the first opening. Since air can flow in stably from the opening of the second opening, it is possible to prevent the contents to be injected and the air to flow in from intersecting with each other in the first opening to cause pulsation. The contents can be smoothly poured out from one opening. Further, since the second score that defines the second opening is continuously formed on the first score that defines the first opening, the first score is operated by operating one tab during the can opening operation. The opening and the second opening can be opened.

However, when the second score is formed continuously with the first score, the total length of the score becomes long. Therefore, in order to open the second opening in addition to the first opening, it is large during the can opening operation. Breaking force is required, and the openness (opening property) deteriorates. On the other hand, in order to maintain good openness of the opening, it is conceivable to reduce (thin) the residual thickness of the score to suppress an increase in breaking force during the can opening operation. In this case, When the internal pressure inside the can rises and buckling occurs, the score may be broken (score out) or the hinge of the opening may be broken. In addition, if the score is broken, the contents inside the can may be leaked.

The present invention has been made in view of such circumstances, and it is possible to prevent breakage of the score and leakage of the contents, and it is possible to easily open the opening at the time of opening the can to improve the openness. An object of the present invention is to provide a can lid having good pouring property, which allows the contents to be poured out quickly and smoothly.

The can lid of the present invention includes a can lid main body and a tab attached to the can lid main body, and the can lid main body has an opening defined by a score and a central portion of the upper surface of the can lid main body. A rivet is formed so as to project to which the tab is attached, and the score has a first score, a second score, and a third score connecting the first score and the second score. The opening is defined by the first score and is defined by the first opening protruding from the peripheral portion of the rivet to the upper peripheral edge of the can lid main body and the second score. It has a second opening protruding in a region opposite to the first opening with the first opening in between, and in a plan view of the upper surface of the can lid body, passes through the center of the rivet and from the rivet of the first score. When the line passing through the farthest position is the Y axis and the line passing through the center of the rivet and orthogonal to the Y axis is the X axis, the end of the second score sandwiches the X axis and the first score is The first score is formed on the peripheral portion of the rivet, and the arc that is convex outward in the radial direction of the can lid body and is connected to the third score. The third score has an intermediate portion of the shape, and the third score is formed at a position including a point where the score intersects the X-axis, and the thickness of the residual thickness portion of the third score is the residual thickness portion of the intermediate portion. It is formed larger than the thickness in the range of 15% or more and 40% or less, and the thickness of the residual thickness portion of the second score is equal to or larger than the thickness of the residual thickness portion of the intermediate portion and the thickness of the residual thickness portion of the third score. The size is less than that, and the length of the third score is 1.5 mm or more and 5.0 mm or less.

The can lid of the present invention has a configuration in which the opening has a first opening overhanging the upper peripheral edge of the can lid main body and a second opening overhanging in a region opposite to the first opening with a rivet in between. Further, by extending the end of the second score that defines the second opening to the region opposite to the first score with the X axis in between, the contents are poured out from the opening of the first opening. At that time, since air can flow in stably from the opening of the second opening, the occurrence of pulsation can be prevented, and the contents can be quickly and smoothly poured out from the opening of the first opening.
Further, in this can lid, the length of the third score connecting between the first score and the second score is formed to be 1.5 mm or more and 5.0 mm or less, and the thickness of the residual thickness portion of the third score is Since it is formed larger (thicker) within the range of 15% or more and 40% or less than the middle part, when the first score is broken and the first opening is opened by the first operation that causes the rear end part of the tab. In addition, the progress of fracture can be braked at the third score in which the depth of the score is shallower than that of the intermediate portion, that is, the thickness of the residual thickness portion is large. In this way, since the breaking of the score is surely stopped in the third score, in the first operation, the first opening and the second opening are surely bent to open only the first opening. be able to.
Then, after opening the first opening (after the first operation), the second opening rotates the tab around the rivet in the extending direction of the second score (performs the second operation) with the tab raised. As a result, it can be easily opened. At this time, since the thickness of the residual thickness portion of the second score is formed to be smaller (thinner) than that of the third score, the breaking force of the second score can be maintained relatively low, and the second opening can be easily opened. ..
If the length of the third score is less than 1.5 mm, that is, less than 1.5 mm, it becomes difficult to reliably stop the breaking of the score at the third score in the first operation. On the other hand, if the length of the third score exceeds 5.0 mm, the resistance when breaking the second score increases in the second operation, and it becomes difficult to open the second opening.
Further, even when the difference between the thickness of the residual thickness portion of the third score and the thickness of the residual thickness portion of the intermediate portion is less than 15% of the thickness of the residual thickness portion of the intermediate portion, the score is broken in the first operation. It becomes difficult to stop at 3 scores. Then, even when the difference between the thickness of the residual thickness portion of the third score and the thickness of the residual thickness portion of the intermediate portion exceeds 40% of the thickness of the residual thickness portion of the intermediate portion, the second score is broken in the second operation. The resistance at the time of making the second opening becomes large, and it becomes difficult to open the second opening.

As described above, in the can lid of the present invention, the first operation for raising the rear end portion of the tab and the second operation for rotating the tab around the rivet are combined to form the first opening and the second opening. It is decided to open the opening, and in the first operation, the propagation of the break of the score is stopped at the third score, and the first opening is bent by bending between the first opening and the second opening to open the first opening. , The breaking force of the score in the first operation can be kept low.
On the other hand, in the second operation, the tab is rotated around the rivet to press the second opening and act to tear the second score, so that the third score formed shallower than the middle portion is used. Even if there is (even if the residual thickness portion is formed thicker than the intermediate portion), it can be easily broken. Further, by forming the third score shallower than the intermediate portion in this way, it is possible to suppress a decrease in the pressure resistance strength of the can lid even though the second score is provided and the total length of the score is long. Therefore, even when the internal pressure inside the can rises and buckling occurs, it is possible to prevent the score from breaking and the contents from leaking.

In the can lid of the present invention, it is preferable that the thickness of the residual thickness portion of the second score is formed to be larger than the thickness of the residual thickness portion of the intermediate portion.

By forming the thickness of the residual thickness portion of the second score larger (thicker) than that of the intermediate portion, it is possible to suppress a decrease in the pressure resistance of the can lid. Therefore, it is possible to form the thickness of the residual thickness portion of the second score smaller than that of the third score, maintain the breaking force of the second score relatively low, and improve the good can openability of the second score. At the same time, by forming the thickness of the residual thickness portion of the second score larger than that of the intermediate portion of the first score, it is possible to surely prevent the score from being broken or the contents from being leaked.

In the can lid of the present invention, it is preferable that the third score is formed by gradually increasing the thickness of the residual thickness portion from the connection side with the intermediate portion to the connection side with the second score.

By forming the residual thickness portion of the third score by increasing it stepwise, it is possible to deeply brake the progress of score breakage each time the step changes.

According to the present invention, even in a can lid having an opening having a first opening and a second opening, it is possible to prevent breakage of the score and leakage of the contents, and the opening can be smoothly opened. It is possible to maintain a good openness and to quickly and smoothly pour out the contents.

It is a top view of the can lid of 1st Embodiment of this invention. It is sectional drawing on the Y axis of the can lid shown in FIG. It is a top view of the main part of the score part of the can lid shown in FIG. It is a cross-sectional view of a main part of the score part of the can lid in the cross-sectional view taken along the line GG shown in FIG. It is a cross-sectional view of a score, (a) shows an intermediate part, and (b) shows a connecting part. It is a top view of the can lid explaining the opening method of the opening, (a) is the state which opened the 1st opening, (b) is the state which opened the 2nd opening, (c) is the opening of the opening. It shows the state where the tab is returned to the original position later. It is a top view of the can lid of the 2nd Embodiment of this invention. FIG. 7 is a plan view of a main part of the score portion of the can lid shown in FIG. 7. It is a main part plan view of the score part of the can lid of the 3rd Embodiment of this invention. 9 is a cross-sectional view of a main part of a score portion of a can lid in a cross-sectional view taken along the line JJ shown in FIG.

Hereinafter, embodiments of the can lid according to the present invention will be described with reference to the drawings.
The can lid 101 of the first embodiment is, for example, a so-called stayion tab type can lid used for cans for beverages and the like, and as shown in FIG. 1, the can lid main body 1A and the can lid main body 1A. It is composed of a tab 2 attached to the. The can lid body 1A and the tab 2 are each made of an aluminum alloy.

As shown in FIG. 1, the can lid main body 1A includes a substantially disk-shaped panel portion 10 and an annular counter sink portion 11 provided so as to be convex downward along the outer peripheral portion of the panel portion 10. It has. A concavely formed panel deboss 12 is provided on the upper surface of the panel portion 10, and a rivet formed on the bottom surface of the panel deboss 12 and protruding from the central portion of the panel portion 10 (can lid body 1A). 13 is formed, and the tab 2 is attached to the rivet 13. Further, an opening 8 defined by the score 3 is formed on the bottom surface of the panel deboss 12, and a finger hook recess 14 is provided on the side opposite to the opening 8 (upper side in FIG. 1), and these rivets are provided. A convex portion 15 called a dimple is formed between the 13 and the finger hook recess 14.

The rivet 13 is integrally formed with the panel portion 10 by performing a coining process for imprinting the upper surface of the panel portion 10 in a ring shape and projecting the central portion of the panel portion 10 upward.
Further, the finger hook recess 14 is formed so as to be along the rear end portion (pulling portion 22) of the tab 2 and in the vicinity thereof, a part of the bottom surface of the panel deboss 12 is further recessed. The opening person can put his / her finger under the rear end portion of the tab 2 from the finger hook recess 14 so that he / she can easily pull up by putting his / her finger on the rear end portion.

The score 3 defines the opening 8, and by pressing the opening 8 with the tab 2 to break the score 3, the opening 8 is pushed into the can and the spout is opened. An auxiliary score 9 formed in parallel adjacent to the score 3 is formed inside the score 3, and the score 3 and the auxiliary score 9 are connected at the start end 31 and the end 39 of the score 3. Has been done. The auxiliary score 9 is formed shallower than the score 3, and is not broken by the pressing of the tab 2.

Then, as shown in FIG. 3, the score 3 has a configuration having a first score 4, a second score 5A, and a third score 6 connecting between the first score 4 and the second score 5A. The opening 8 is composed of a first opening 81 defined by a first score 4 and a second opening 82 defined by a second score 5A. Of these, the first opening 81 is formed so as to project from the peripheral portion of the rivet 13 to the upper peripheral edge portion of the can lid main body 1A, and the second opening 82 is opposite to the first opening 81 with the rivet 13 interposed therebetween. It is formed overhanging the area.

As shown in FIG. 3, the first score 4 includes a start end portion 31 formed around the peripheral portion of the rivet 13 and connected to the start end portion of the auxiliary score 9, and an arcuate concave arc portion 32 that surrounds the rivet 13 approximately half. The can lid body 1A has an arc-shaped intermediate portion 33 which is convex outward in the radial direction and is connected to the third score 6, and has a first opening portion as shown by hatching in the lower portion of FIG. 81 is defined. Further, the first opening 81 is a first hinge portion between the start end portion 31 of the first score and the third score 6 formed continuously in the intermediate portion 33, as shown by a broken line in FIG. It is formed with some C1 left. The starting end portion 31, the concave arc portion 32, the intermediate portion 33, and the third score 6 constituting the first score 4 are loosely connected by sharing a tangent line at the end points where they are connected to each other.
The concave arc portion 32 is formed in a ring-shaped printing pressure portion crushed by coining around the rivet 13, and becomes an initial fracture portion when the opening 8 is pressed by the tab 2.

As shown in FIGS. 1 and 3, the third score 6 passes through the center O1 of the rivet 13 and is the farthest position from the rivet 13 of the first score 4 (can lid body) in the plan view of the upper surface of the can lid body 1A. When the line passing through the point P1) at the outermost peripheral position of 1A is defined as the Y axis and the line passing through the center O1 of the rivet 13 and orthogonal to the Y axis of the first score 4 is defined as the X axis, the score 3 intersects the X axis. It is formed at a position including the point Q1 to be formed, and its length L (see FIG. 4) is provided to be 1.5 mm or more and 5.0 mm or less. Further, the third score 6 is formed to be shallower than the intermediate portion 33 of the first score 4, and as shown in FIG. 4, the remaining of the third score 6 (first stage 34a, second stage 34b). The thicknesses E31 and E32 of the thick portion are formed larger (thicker) within a range of 15% or more and 40% or less than the thickness E11 of the remaining thickness portion of the intermediate portion 33, respectively. Therefore, in the third score 6 in which the thickness of the residual thickness portion is formed large when the first score 4 is broken and the first opening 81 is opened by the first operation that causes the rear end portion of the tab 2. By braking the progress of the break, the break of the score 3 is stopped.

If the total length L of the third score is less than 1.5 mm, that is, less than 1.5 mm, it becomes difficult to reliably stop the breakage of the score 3 at the third score 6 in the first operation. On the other hand, when the length L of the third score 6 exceeds 5.0 mm, the breakage of the score 3 can be stopped at the third score, but the resistance is large during the second operation of breaking the second score 5A. Therefore, it becomes difficult to open the second opening 82.

Further, when the difference between the thicknesses E31 and E32 of the residual thickness portion of the third score 6 and the thickness E11 of the residual thickness portion of the intermediate portion 33 is less than 15% of the thickness E11 of the residual thickness portion of the intermediate portion 33, the third score 6 is also obtained. It becomes difficult to stop the breakage of the score 3 at the third score 6 in one operation. Then, when the difference between the thicknesses E31 and E32 of the residual thickness portion of the third score 6 and the thickness E11 of the residual thickness portion of the intermediate portion 33 exceeds 40% of the thickness E11 of the residual thickness portion of the intermediate portion 33, the second In the operation, the resistance when breaking the second score 5A becomes large, and it becomes difficult to open the second opening 82.

As shown in FIG. 5A and the cross section of the intermediate portion 33 of the first score 4 and in FIG. 5B the cross section of the first stage 34a of the third score 6, the score 3 increases toward the bottom of the blade. It is formed in a symmetrical inverted trapezoidal shape in which the opening width is narrowed, and the opening angle α of both side surfaces is formed to be, for example, 50 °. Further, the score 3 has a part of both side surfaces continuous from the start end portion 31 of the first score 4 to the concave arc portion 32, the intermediate portion 33, the third score 6, the extension portion 38 of the second score 5A, and the end portion 39. It is formed, and the depth of the score 3 at each position is set by changing the height of the blade bottom.

Further, in the can lid 101, as shown in FIG. 4, the third score 6 increases the thickness of the residual thickness portion from the connection side with the intermediate portion 33 to the connection side with the second score 5A (stretched portion 38). It is formed in a shape that is gradually increased. In the example shown in FIG. 4, the third score 6 is composed of a first stage 34a formed shallower than the intermediate portion 33 and a second stage 34b formed shallower than the first stage 34a. The thickness E32 of the residual thickness portion of the second stage 34b is formed larger than the thickness E31 of the residual thickness portion of 34a. As a result, in the third score 6, the progress of the breakage of the score 3 is deeply braked each time the step changes, such as from the intermediate portion 33 to the first stage 34a and from the first stage 34a to the second stage 34b. It has become.
In the example shown in FIG. 4, the first stage 34a and the second stage 34b constituting the third score 6 are provided with the same length (equal), but the total length of the third score 6 is If L can be provided at 1.5 mm or more and 5.0 mm or less, the length can be changed for each step.

The first hinge portion C1 is a portion that is bent when the first opening 81 is opened by the first operation, and as shown in FIG. 3, the breaking arrival point of the starting end portion 31 and the breaking reaching point of the third score 6. It is formed so as to connect with. Therefore, the position of the first hinge portion C1 slightly varies depending on how far the start end portion 31 and the third score 6 are broken.

As shown in FIG. 3, the second score 5A is a terminal formed continuously with the third score 6 and connected to the extension portion 38 extending to the region opposite to the rivet 13 and the terminal portion of the auxiliary score 9. The third score 6 and the extension portion 38, and the extension portion 38 and the end portion 39 are formed by a straight line or a curved line having a large radius of curvature, and share a tangent line at the end points where they are connected to each other. And are loosely connected. Further, as shown in FIG. 1, in the second score 5A, in a plan view of the upper surface of the can lid main body 1A (panel portion 10), the end of the second score 5A (score 3) is the first with the X axis in between. It extends to the region opposite the score 4. The second score 5A is formed by leaving a part of the second hinge portion C2 between the center O1 of the rivet 13 and the end portion of the score 3 (the end portion 39 of the second score 5A) as shown by a broken line. As shown by the hatching of the upper portion of FIG. 3, the second opening 82 continuous with the first opening 81 is defined.

The second hinge portion C2 is a portion that is bent when the second opening 82 is opened by the second operation of rotating the tab 2, and as shown in FIG. 3, the breaking arrival point of the end portion 39 and the center of the rivet 13 It is formed so as to connect with O1. Therefore, the position of the second hinge portion C2 slightly varies depending on how far the end portion 39 is cut.

Further, the second score 5A (stretched portion 38 and the terminal portion 39) is formed below the depth of the intermediate portion 33 and deeper than the third score 6. That is, the thickness E21 of the residual thickness portion of the second score 5A is equal to or greater than the thickness E11 of the residual thickness portion of the intermediate portion 33 and the thickness of the residual thickness portion of the third score 6 (here, the thickest second stage E32). It is formed to a size less than (thickness). In this way, by forming the third score 6 with a predetermined thickness and length, which is shallower than the intermediate portion 33 (the thickness of the residual thickness portion is increased), the second score 5A is provided and the total length of the score 3 is lengthened. Despite the formation, it is possible to suppress a decrease in the pressure resistance of the can lid 101.
In the case shown in FIG. 4, the second score 5A (stretched portion 38) is formed deeper than the third score 6 (both the first stage 34a and the second stage 34b), and is formed shallower than the intermediate portion 33. Has been done. That is, the thickness E21 of the residual thickness portion of the second score 5A is formed to be smaller than the thicknesses E31 and E32 of the residual thickness portion of the third score 6 and larger than the thickness E11 of the residual thickness portion of the intermediate portion 33. .. By forming the thickness of the residual thickness portion of the second score 5A smaller than that of the third score 6 in this way, the breaking force of the second score 5A can be maintained relatively low, so that the second opening 82 can be easily formed. Can be opened.

In the can lid 101 of the present embodiment, as shown in FIG. 3, two intersections P1 and P2 where the Y-axis and the first score 4 (first opening 81) intersect in a plan view of the can lid main body 1A. Assuming that the direction facing the intersection P2 at the tip of the first score 4 is 0 o'clock (the direction of the intersection P1) with reference to the intermediate position O2 of the third score 6, the length L of the third score 6 is 3 mm at the position of about 10:30. Is formed of. The thickness of the residual thickness portion of the first score 4 is 0.085 mm to 0.100 mm at the position (thickness E11) of the intermediate portion 33 from 3 o'clock to 10 o'clock, and the thickness of the residual thickness portion of the third score 6 is set to 0.085 mm to 0.100 mm. (Thickness E31, E32) is set to 0.100 mm to 0.125 mm, and the thickness E31, E32 of the residual thickness portion of the third score 6 is the thickness E11 of the residual thickness portion of the intermediate portion 33 from 3:00 to 10:00. It is set to be larger in the range of 15% or more and 40% or less. Further, the thickness of the residual thickness portion at the position (intersection point Q2) where the first score 4 overlaps on the tip end side of the tab 2 is set to be larger than the thickness of the residual thickness portion before and after that.

Further, the thickness E21 of the residual thickness portion of the second score 5A is set so that the stretched portion 38 is 0.100 mm to 0.110 mm, and the residual thickness of the stretched portion 38 and the terminal portion 39 of the second score 5A is set. The thickness of the portion is formed smaller than that of the third score 6, but is formed larger than that of the intermediate portion 33 between 3:00 and 10:00.

Further, in this can lid 101, the distance from the center O1 of the rivet 13 to the side end portion (point U1) in the width direction (X-axis direction) of the tab 2 is A, and the score is from the center O1 of the rivet 13 on the X-axis. When the distance to 3 (in this case, the third score 6) is B, the distance A is formed smaller than the distance B, and the score 3 is rivet than the lateral end portion (point U1) of the tab 2 in the width direction. It is arranged away from the center O1 of 13.

In this case, the difference (BA) between the distance B and the distance A is preferably formed to be 0.3 mm or more and 3.0 mm or less. As the difference (BA) becomes larger, the score 3 and the tab 2 are arranged apart from each other. Therefore, by setting the difference (BA) to 0.3 mm or more, the tab 2 and the score end face are separated from each other. Contact can be reliably avoided, and the second opening 82 can be opened smoothly. Further, by setting the difference (BA) to 3.0 mm or less, the position of the score 3 is set from the point of action where the tab 2 and the opening 8 (the first opening 82 and the second opening 82) come into contact with each other. Since it can be arranged at a close position, the breaking force of the score 3 (second score 5A) required for the can opening operation can be made relatively small, and good openness can be ensured. When the difference (BA) is set to a size exceeding 3.0 mm, the position of the score 3 is far from the point of action where the tab 2 and the opening 8 come into contact with each other, so that a large breaking force is required during the can opening operation. And the openness becomes worse.

Further, as shown in FIGS. 1 and 3, the first opening 81 defined by the first score 4 has an opening length on the Y axis of H (Y) in a plan view of the upper surface of the can lid main body 1A. The ratio (W / H) of the maximum width W to the opening length H is 0 when the maximum width parallel to the X axis is W as the distance between the intersections P1 and P2 of the axis and the first score 4. It is formed in a size of 7. or more and 1.4 or less. As described above, since the maximum width W of the first opening 81 is formed to be the same as the opening length H and is formed in a relatively narrow shape, the first opening 81 is poured out from the opening of the first opening 81. The width of the flow of contents can be narrowed. In this case, the ratio (W / H) of the maximum width W and the opening length H is preferably set to 1.2 or less. By limiting the first opening 81 to a size such that the ratio (W / H) is 0.7 or more and 1.2 or less, more stable pouring property can be obtained.

When the ratio (W / H) exceeds 1.4, the opening of the first opening 81 becomes wide, so that a large amount of contents are vigorously poured out from the wide first opening 81. Some of the contents may come off the container and spill. In addition, when the content is directly drunk from the opening of the first opening 81, a part of the content may come off from the mouth and spill. On the other hand, when the ratio (W / H) is less than 0.7, the opening area of the first opening 81 becomes smaller, and a sufficient amount of the contents poured out from the opening of the first opening 81 can be secured. It gets harder.

Further, on the opening 8, inner beads 41 and 42 protruding from the upper surface are formed along the score 3 and the auxiliary score 9 for reinforcement. The inner beads 41 and 42 are preferably formed in portions other than the first hinge portion C1 and the second hinge portion C2. The inner bead 41 formed on the first opening 81 surrounds the vicinity of the center of the first opening 81 (near the point O2) and is along the intermediate portion 33 of the first score 4 and of the can lid body 1A. It has a convex shape along the outer radial direction. Further, the inner bead 42 formed on the first opening 81 like the inner bead 41 is formed along the score 3 at a position close to the third score 6.

Further, the convex portion 15 formed between the rivet 13 and the finger hook concave portion 14 is formed in a region opposite to the second opening 82 with the rivet 13 (Y-axis) interposed therebetween. The convex portion 15 projects to the bottom surface of the panel deboss 12, and as shown in FIG. 1, in the state before the tab 2 is pulled up, the lower surface of the outer edge portion of the tab 2 is caught by the convex portion 15, so that the tab 2 is rivet. Rotational movement around 13 is prevented.

The tab 2 is attached to the rivet 13 as described above, and when the longitudinal direction of the tab 2 is arranged parallel to the Y axis of the can lid body 1A at one end of the tab body 2, the first opening 81 A pressing portion 21 is formed so as to be overlapped on the upper side, and a pulling portion 22 is formed at the other end portion arranged on the opposite side of the rivet 13 (X-axis).
As shown in FIGS. 1 and 3, the pressing portion 21 is formed in an arc shape, and a tongue portion 24 is formed by a U-shaped slot 23 between the pressing portion 21 and the pulling portion 22 to form a tongue. A rivet hole (not shown) is formed in the portion 24. Then, the rivet 13 is inserted into the rivet hole, and the tab 2 is attached to the can lid body 1A in a state where the lower surface of the tongue portion 24 is in contact with the upper surface of the panel deboss 12 (can lid body 1A). Further, a tab hole portion 25 that opens in the thickness direction of the tab 2 is formed in the pulling portion 22 of the tab 2.

Next, a method of opening the opening 8 in the can lid 101 configured as described above will be described.
(First operation)
First, in a state where the pressing portion 21 of the tab 2 is overlapped with the first opening 81 (state in FIG. 1), the first operation of pulling up the pulling portion 22 of the tab 2 is performed. When the pulling portion 22 of the tab 2 is pulled up, the pressing portion 21 of the tab 2 comes into contact with the upper surface of the first opening 81, and the pressing portion 21 serves as a fulcrum to lift the rivet 13 upward. At this time, the portion of the concave arc portion 32 of the first score 4 on the first opening 81 side is in a state of being pressed by the tab 2, and the portion of the concave arc portion 32 on the rivet 13 side is lifted upward. Shear force acts on the concave arc portion 32 to break it (pop operation). Since the first opening 81 is reinforced by the inner bead 41 and the deformation is suppressed, a shearing force can be reliably applied to the concave arc portion 32, and the concave arc portion 32 can be smoothly broken.

Then, when the pulling portion 22 of the tab 2 is further lifted, the rivet 13 becomes a fulcrum, the pressing portion 21 of the tab 2 becomes an action point, and the first opening 81 surrounded by the first score 4 becomes the inside of the can by the tab 2. The first score 4 is sequentially broken while being pushed into the first opening 81 so as to orbit the first opening 81 (tier operation). Then, when the break of the score 3 reaches the third score 6, the brake is surely applied at the third score 6 in which the thickness of the residual thickness portion is formed larger than that of the intermediate portion 33, and the break progress of the score 3 is stopped. To. Next, the stress is concentrated on the breaking stop point of the third score 6, and the first hinge portion C1 of the connecting portion between the third score 6 and the start end portion 31 is bent. Then, when the first opening 81 is pushed into the can, the first opening 81o opens as shown in FIG. 6A.

(Second operation)
After that, as shown by an arrow T in FIG. 6A, the second tab around the rivet 13 is maintained in a state where the tab 2 is raised (a state in which the tab 2 is raised substantially perpendicular to the upper surface of the can lid body 1A). By performing the second operation of rotating and twisting the score 5A in the extending direction (clockwise T direction), the second opening 82 between the second score 5A and the rivet 13 is pressed by the side end portion of the tab 2. To do. At this time, the distance A from the center O1 of the rivet 13 to the side end portion (point U1) of the tab 2 is formed to be smaller than the distance B from the center O1 of the rivet 13 to the score 3 (here, the first score 4). Therefore, even if the tab 2 is rotated with the tab 2 raised, it is possible to prevent the tab 2 from coming into contact with the broken score end face. As the tab 2 rotates, as shown in FIG. 6B, the second opening 81 is pushed down into the can, the second score 5A is torn, and the second score 5A is terminated from the extending portion 38. Breaking progresses sequentially toward the portion 39, and the second hinge portion C2 is bent. Then, the second opening 82 is pushed into the can, and the second opening 82o opens in the region opposite to the first opening 81o with the rivet 13 interposed therebetween.

Further, by the second operation, the first opening 81 connected to the second opening 82 via the first hinge portion C1 is further pushed into the can, so that the first opening 81o of the first opening 81 can be used. The area of the part facing the outside becomes smaller. In this way, after the first score 4 is broken by the first operation, the second score 5A is continuously broken by the second operation, so that the side opposite to the first opening 81 sandwiching the X-axis (rivet 13) is opposite. A second opening 82 is opened in the region following the first opening 81, and an opening 80o having an opening area S1 of the first opening 81 and an opening area S2 of the second opening 82 is formed.

Then, after breaking the second score 5A to open the opening 8, the tab 2 is returned to the original position as shown in FIG. 6 (c).
When the first score 4 is broken to open the first opening 81 (first opening 81o) and then the tab 2 is tilted to the original position without being rotated to return to the state before opening. It is possible to maintain a state in which only the first opening 81 is opened without opening the second opening 82. As described above, in the can lid 101, since the third score 6 exists, the opening of the opening 8 can be stopped once before the complete opening (opening 80o), and the normal opening (second) can be stopped by operating the tab 2. It is an opening only in the area to be opened in a normal can lid without a score 5A, and consumes an opening corresponding to the first opening 81o in the present embodiment) and a complete opening (opening 80o opened to the second opening 82o). Can choose.

As described above, in the can lid 101 of the present embodiment, the openings 8 (first openings 81 and second) defined by the first score 4 and the second score 5A on the upper surface of the can lid main body 1A. The opening 82) is connected by the second hinge portion C2, and the second operation of rotating the tab 2 around the rivet 13 after the first operation causes the first score 4 and the third score 6 to be consecutively second. When the 2 score 5A is broken, the first opening 81 is pushed into the can together with the second opening 82, so that the can lid main body 1A includes the first opening 81 and the second opening 82. The opening 8 is opened so that an opening 80o having a large opening area is formed. Then, the end of the second score 5A that defines the second opening 82 is extended to the region opposite to the first score 4 with the rivet 13 (X-axis) interposed therebetween, so that the first opening 81 is the first. When the contents are poured out from the 1 opening 81o, air can stably flow in from the 2nd opening 82o of the 2nd opening 82, so that the occurrence of pulsation can be prevented and the contents can be discharged to the outside from the 1st opening 81o. Can be poured out quickly and smoothly.

Further, in the can lid 101, the opening 8 is composed of the first opening 81 and the second opening 82, and the first hinge portion C1 and the second hinge portion C2 are bent in order to open the opening 8. Since the structure is such that 80o is opened, the first opening 81 opened first can be deeply folded inside the can together with the opening of the second opening 82. As a result, the portion where the opening 8 covers the first opening 81o of the first opening 81 and faces the outside from the opening can be reduced. Therefore, when the can is tilted and the contents flow out from the first opening 81o of the first opening 81 toward the outside, it is possible to avoid the opening 8 becoming an obstacle and causing pulsation, and the first opening The contents can be smoothly poured out from the first opening 81o of 81.

Further, in the can lid 101, the first operation for causing the tab 2 and the second operation for rotating the tab 2 around the rivet 13 are combined to open the first opening 81 and the second opening 82. In the first operation, the propagation of the break of the score 3 is surely stopped at the third score 6, and the first opening 81 is bent between the first opening 81 and the second opening 82. Therefore, the breaking force of the score 3 (first score 4) in the first operation can be kept low.

On the other hand, in the second operation, the tab 2 is rotated around the rivet 13 to press the second opening 82 and act to tear the second score 5A, so that the tab 2 is formed shallower than the intermediate portion 33. Even if the third score is 6 or the second score is 5A, that is, even if the thickness of the residual thickness portion is formed larger than that of the intermediate portion 33, the fracture can be easily performed. Further, by forming the thickness E21 of the residual thickness portion of the second score 5A smaller than the thickness E31 and E32 of the residual thickness portion of the third score 6, the breaking force of the second score 5A can be maintained relatively low, and the second score 5A can be maintained relatively low. 2 The openability of the opening 82 can be improved.
Then, when the second score 5A is formed deeper than the third score 6 and shallower than the intermediate portion 33 in this way, the second score 5A is provided to form the total length of the score 3 longer. Despite this, it is possible to suppress a decrease in the pressure resistance of the can lid 101. Therefore, even when the internal pressure inside the can rises and buckling occurs, it is possible to prevent breakage of the score 3 and leakage of the contents.

In the can lid 101 of the first embodiment, the second score 5A was formed relatively short, and the end portion 39 was formed by a straight line or a gently curved line continuous with the extension portion 38, but the extension portion 38 was formed. And the shape of the end portion 39 is not limited to this. For example, when the total length of the second score 5B is formed long as in the can lid 102 (can lid main body 1B) of the second embodiment shown in FIGS. 7 and 8, the end portion 39 of the second score 5B is used. It may be curved and formed within the area of the back surface of the tab 2. Specifically, the terminal portion 39 may be formed in the region between the rivet 2 of the panel portion 10 and the finger hook recess 14, and may be formed as close to the rivet 2 as possible.
The tab 2 is the same as that of the first embodiment, and in FIGS. 7 and 8, the elements common to the first embodiment are designated by the same reference numerals and the description thereof will be omitted.

In the can lid 102 of the second embodiment as well, the length of the third score 6 is formed to be 1.5 mm or more and 5.0 mm or less as in the can lid 101 of the first embodiment, and the residual thickness of the third score 6 is formed. By forming the thickness of the portion larger in the range of 15% or more and 40% or less than the thickness of the remaining thickness portion of the intermediate portion 33, the first score 4 is broken by the first operation and the first opening 81 is opened. At that time, the breakage of the score 3 can be reliably stopped at the third score 6 in which the depth of the score 3 is shallower than that of the intermediate portion 33, that is, the thickness of the residual thickness portion is large, and the first opening 81 and the first opening 81 The first opening 81 can be opened by surely bending between the two openings 82.
Then, after opening the first opening 81 (after the first operation), the second opening 82 rotates the tab 2 around the rivet 13 in the stretching direction of the second score 5B with the tab 2 raised (after the first operation). By performing the second operation), the opening can be easily performed.

In order to increase the opening area S2 of the second opening 82 as in the can lid 102 of the second embodiment, it is necessary to increase the total length of the second score 5B, but the total length of the second score 5B is As the length increases and the position of the end portion 39 becomes farther from the center O1 of the rivet 2, the distance between the position of the second score 5B and the pressing portion of the second opening 82 by the tab 2 becomes longer (farther). The breaking force required to break the 2 score 5B tends to increase. In this respect, as in the can lid 102 of the second embodiment, the terminal portion 39 of the second score 5B is bent and formed without being significantly separated from the rivet 2, so that the tab 2 is rotated when the tab 2 is rotated. It can be formed without significantly increasing the distance between the position of the score 5B and the pressing portion of the second opening 82 by the tab 2. Therefore, the breaking force of the second score 5B required at the time of opening the can of the second score 5B is not increased, and it is possible to avoid putting a heavy burden on the finger when rotating the tab 2, so that the opening area can be avoided. The large second opening 82 of S2 can be reliably opened.

Further, if the end portion 39 of the second score 5B is formed close to the peripheral edge portion of the panel portion 10, the pressure resistance strength of the can lid 102 is likely to decrease. Therefore, by keeping the forming position of the terminal portion 39 in the peripheral region of the rivet 2, it is possible to avoid a decrease in the pressure resistance of the can lid 102.
Further, as in the can lid 102 of the second embodiment, the formation range of the second score 5B is contained within the range of the back area of the tab 2, so that the total length of the second score 5B is lengthened and the second opening is opened. Even when the opening area S2 of the portion 82 is formed to be large, the opening portion of the second opening 82 can be hidden behind the tab 2, so that it is possible to avoid spoiling the appearance.

Next, the can lid 103 of the third embodiment of the present invention shown in FIG. 9 will be described.
In the can lid 103 of the third embodiment, as shown in FIGS. 9 and 10, the score 3 has a first score 4 and a second score 5C formed continuously to the first score 4. It is composed. Then, as shown in FIG. 9, the second score 5C is formed at a position including the point where the score 3 intersects the X-axis, and the thickness E22 of the residual thickness portion of the second score 5C is the residual thickness of the first score 4. It is formed larger (thicker) in the range of 15% or more and 40% or less than the thickness E11 of the portion.
In the can lid 103 of the third embodiment, a part of the configuration of the tab 2 and the like is the same as that of the first embodiment, and in FIGS. 9 and 10, the elements common to the first embodiment have the same reference numerals. Is added to omit the description.

In this can lid 103, when the first score 4 is broken and the first opening 81 is opened by the first operation that causes the rear end portion of the tab 2, the score is deeper than the intermediate portion 33 of the first score 4. In the second score 5C in which the shallowness is shallow, that is, the thickness of the residual thickness portion is large, the progress of the breakage of the score 3 can be braked. Then, the thickness E22 of the residual thickness portion of the second score 5C is formed larger (thicker) than the thickness E11 of the residual thickness portion of the first score 4 within a range of 15% or more and 40% or less, so that the first score 4 The breakage of the score 3 can be reliably stopped in the first half portion of the second score 5C (within the range of the length N = 5 mm from the start end of the second score 5C) continuous with the intermediate portion 33 of the second score. Therefore, in the first operation, the first opening 81 can be reliably bent between the first opening 81 and the second opening 82 to open the first opening 81. It is formed in the connecting portion between the range of the length N of the first half portion of the first hinge portion C1 and the starting end portion 31 of the first score 4.

Then, after opening the first opening 81 (after the first operation), the second opening 82 rotates the tab 2 around the rivet 13 in the stretching direction of the second score 5C with the tab 2 raised (after the first operation). By performing the second operation), the opening can be easily performed. At this time, the thickness E22 of the residual thickness portion of the second score 5C is formed to be large within a range of 15% or more and 40% or less of the thickness E11 of the residual thickness portion of the intermediate portion 33, so that the second score 5C is broken. Since it is possible to avoid an extremely high force and the breaking force of the second score 5C can be maintained relatively low, the second opening 82 can be easily opened. Further, the thickness E22 of the residual thickness portion of the second score 5C is formed to be large within the range of 15% or more and 40% or less of the thickness E11 of the residual thickness portion of the intermediate portion 33, so that the second score 5C is provided and the score 3 is provided. Despite the fact that the total length of the can lid 103 is long, it is possible to suppress a decrease in the pressure resistance of the can lid 103. Therefore, even when the internal pressure inside the can rises and buckling occurs, it is possible to prevent breakage of the score 3 and leakage of the contents.

If the difference between the thickness E22 of the residual thickness portion of the second score 5C and the thickness E11 of the residual thickness portion of the intermediate portion 33 is less than 15% of the thickness E11 of the residual thickness portion of the intermediate portion 33, the first operation is performed. In, it becomes difficult to stop the breakage of the score 3 at the first half portion (length N) of the second score 5C. In addition, the pressure resistance of the can lid 103 is lowered, and when buckling occurs, the score 3 may be broken. Then, when the difference between the thickness E22 of the residual thickness portion of the second score 5C and the thickness E11 of the residual thickness portion of the intermediate portion 33 exceeds 40% of the thickness E11 of the residual thickness portion of the intermediate portion 33, in the second operation. , The resistance when breaking the second score 5C becomes large, and it becomes difficult to open the second opening 82.

Hereinafter, Examples and Comparative Examples performed for confirming the effect of the present invention will be described.
Can lids (nominal diameter 206, original plate thickness 0.280 mm before molding) under the conditions shown in Table 1 below were prepared, and the opening performance (opening property) and pressure resistance performance of these can lids were evaluated. In addition, No. For the can lids 1 to 8, the score is composed of the first score, the second score, and the third score, and each dimension corresponds to the dimension shown in FIG. Then, No. in Table 2 For the can lids 9 to 11, the score is composed of the first score and the second score, and each dimension corresponds to the dimension shown in FIG. In addition, No. In the can lid of 1, the third score is formed at two depths, and the first half of the first stage connected to the middle part and the second half of the second stage connected to the second score are each second. It was formed with a length of half (1.5 mm) of the total length L of 3 scores. In addition, No. In the can lids 2 to 8, since the third score was formed in one step without forming in a plurality of steps, the column of "second step" in Table 1 was represented by "-".

(Aperture performance)
After forcibly pulling up the tab pulling part with each can lid fixed, the tab is rotated clockwise around the rivet to open the first opening and the second opening in order, and the opening performance. It was confirmed.
The opening performance was confirmed by 50 pieces for each can lid under the conditions shown in Table 1 or Table 2. Then, when the first operation of pulling up the tab is performed, No. For 1 to 8, the third score, No. For 9 to 11, if there is even 1 out of 50 can lids that do not stop breaking within the range of the length N = 5 mm of the first half of the second score, or after the first operation, the tab is rotated. When two operations were performed, the number of semi-open can lids that did not open until the end of the score (second score) was even 1 out of 50, and any of the cases was evaluated as "x". In addition, all 50 can lids were No. 1 in the first operation. For 1 to 8, the third score, No. For 9 to 11, the case where the fracture stopped within the range of the length N = 5 mm of the first half of the second score and the opening to the end of the score was possible in the second operation after the first operation was evaluated as “◯”.

(Withstand voltage performance)
The pressure resistance performance is evaluated by wrapping each can lid around an empty can body, cutting the can body at an intermediate position, and then using a pressure resistance test device manufactured by Floris Enterprise Co., Ltd. for 100 kPa / 30 seconds. Water pressure was applied at the boosting speed, and a pressure resistance test was performed to measure the pressure when a buckling phenomenon called cornering, in which a part of the can lid partially protrudes, or score cracking occurred. Then, the product in which buckling and score cracking did not occur up to 700 kPa was evaluated as a good product "○", and the product in which buckling and score cracking occurred was evaluated as "x".

As can be seen from Table 3, the thicknesses E31 and E32 of the residual thickness portion of the third score are formed larger than the thickness E11 of the residual thickness portion of the intermediate portion within a range of 15% or more and 40% or less, and the thickness of the third score is increased. With the can lid (No. 1-3, 6) having a length L of 1.5 mm or more and 5.0 mm or less, the breakage of the score can be stopped at the third score in the first operation, and the break of the score after the first operation can be stopped. In the second operation, the score could be reliably broken to the end, and good opening performance was obtained. Further, with respect to these can lids, the thickness E21 of the residual thickness portion of the stretched portion of the second score is formed to be equal to or larger than the thickness E11 of the residual thickness portion of the intermediate portion, and good pressure resistance performance can be exhibited in the pressure resistance test. It was. On the other hand, in the can lid (No. 5) in which the thickness E31 of the residual thickness portion of the third score is made larger than the thickness E11 of the residual thickness portion of the intermediate portion within a range of less than 15%, the score is broken in the first operation. The brakes on the progress were shallow, and it was not possible to stop the score breaking at the third score. Further, in the can lid (No. 4) in which the thickness E31 of the residual thickness portion of the third score is made larger than the thickness E11 of the residual thickness portion of the intermediate portion within a range exceeding 40%, the can is opened to the end of the score. I couldn't do it, and the can was half-opened. Then, in the can lid (No. 7) in which the length L of the third score was formed to be less than 1.5 mm, the breakage of the score could not be stopped at the third score in the first operation. Further, in the can lid (No. 8) in which the length L of the third score exceeds 5.0 mm, the can could not be opened to the end of the score in the second operation, and the can was half-opened.

Further, for the can lid (No. 9) in which the thickness E22 of the residual thickness portion of the second score is formed larger than the thickness E11 of the residual thickness portion of the intermediate portion within a range of 15% or more and 40% or less, the first operation is performed. In the second operation after the first operation, the breaking of the score could be stopped within the range of the length N = 5 mm of the second score, and the breaking could be surely reached to the end of the score in the second operation after the first operation, and good opening performance was obtained. In addition, this No. With respect to the 9-can lid, good pressure resistance performance could be exhibited in the pressure resistance test.
On the other hand, in the can lid (No. 11) in which the thickness E22 of the residual thickness portion of the second score is made larger than the thickness E11 of the residual thickness portion of the intermediate portion within a range of less than 15%, the second score is obtained in the first operation. It was not possible to stop the score breaking within the range of length N = 5 mm. Further, in the can lid (No. 10) in which the thickness E22 of the residual thickness portion of the second score is made larger than the thickness E11 of the residual thickness portion of the intermediate portion within a range exceeding 40%, the can is opened to the end of the score. The can was half-opened.
From the above results, No. By adjusting the thickness and length of the remaining thickness of the score like the can lids of 1, 3, 6 and 9, the opening performance (opening property) of the score can be improved and the pressure resistance is good. Performance can be maintained.

The present invention is not limited to the configuration of the above embodiment, and various changes can be made in the detailed configuration without departing from the spirit of the present invention.

1A, 1B Can lid body 2 Tab 3 Score 4 1st score 5A, 5B, 5C 2nd score 6 3rd score 8 Opening 9 Auxiliary score 10 Panel part 11 Counter sink part 12 Panel deboss 13 Rivet 14 Finger hook concave part 15 Convex part 21 Pressing part 22 Pulling part 23 Slot 24 Tongue part 25 Finger hole part 31 Starting end part 32 Concave arc part 33 Intermediate part 34 Connecting part 38 Extension part 39 Ending part 41, 42 Inner bead 80o Opening 81 First opening 81o First opening 82 Second opening 82o Second opening 101, 102, 103 Can lid C1 First hinge part C2 Second hinge part

Claims (3)

It is provided with a can lid body and a tab attached to the can lid body.
The can lid main body is formed with an opening defined by a score and a rivet that protrudes from the center of the upper surface of the can lid main body to which the tab is attached.
The score has a first score, a second score, and a third score connecting between the first score and the second score.
The opening is
A first opening defined by the first score and protruding from the peripheral portion of the rivet to the upper peripheral edge portion of the can lid main body,
It has a second opening defined by the second score and overhanging a region opposite to the first opening with the rivet in between.
In a plan view of the upper surface of the can lid body,
When the line passing through the center of the rivet and passing through the position farthest from the rivet of the first score is defined as the Y axis, and the line passing through the center of the rivet and orthogonal to the Y axis is defined as the X axis.
The end of the second score is extended to the region opposite to the first score across the X axis.
The first score has a start end portion formed in a peripheral portion of the rivet and an arc-shaped intermediate portion that is convex outward in the radial direction of the can lid main body and is connected to the third score.
The third score is formed at a position including a point where the score intersects the X axis.
The thickness of the residual thickness portion of the third score is formed larger than the thickness of the residual thickness portion of the intermediate portion within a range of 15% or more and 40% or less.
The thickness of the residual thickness portion of the second score is formed to be greater than or equal to the thickness of the residual thickness portion of the intermediate portion and less than the thickness of the residual thickness portion of the third score.
A can lid characterized in that the length of the third score is formed to be 1.5 mm or more and 5.0 mm or less. The can lid according to claim 1, wherein the thickness of the residual thickness portion of the second score is formed to be larger than the thickness of the residual thickness portion of the intermediate portion. Claim 1 or 2 is characterized in that the third score is formed by gradually increasing the thickness of the residual thickness portion from the connection side with the intermediate portion to the connection side with the second score. Can lid as described in.

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