JP4480877B2 - Easy-to-open can lid - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an easy-to-open can lid in which opening pieces that are easily opened by being pushed down toward the inside of the can are partitioned by score lines.
[0002]
[Prior art]
Conventionally, as an easy-to-open can lid that can be opened without using a special instrument (easy open end), a lid of a type in which an opening piece defined on a can lid by a score line is pushed down by a tab is known. . However, with this type of lid, it is necessary to manufacture a tab separately from the panel portion constituting the can lid, which disadvantageously increases the manufacturing process and increases the manufacturing cost. For this reason, various easy open ends that do not use tabs have been proposed, and examples thereof are described in, for example, Japanese Patent Application Laid-Open No. 2000-203573 and Japanese Utility Model Publication No. 57-42818.
[0003]
In the invention described in Japanese Patent Laid-Open No. 2000-203573, a skirt wall is formed by extending upward from the annular groove toward the center axis side of the can body in the lid member, and a recess is formed at the upper end thereof. Yes. In the panel portion inside the hollow portion, an opening piece that is partitioned into a substantially circular shape with a part thereof is formed by a score line. When opening the can lid, the opening piece is pushed down into the container body while breaking the score line by pressing the opening piece, and the opening piece is suspended from the panel portion.
[0004]
In this type of can lid, in order to further reduce the force required for the opening operation and further improve the openability, the entire score line or a part thereof is configured as a line obtained by completely cutting the panel portion in the thickness direction. It is also possible. In such a configuration, since it is necessary to prevent leakage of the contents, on the score line that completely cuts the panel portion and the portion adjacent thereto, the lower side (side that becomes the inner surface of the can) The plastisol will be applied. In addition, this plastisol conceals the metal which is a raw material of a can lid in place of the damaged film by forming a score line, and functions to prevent corrosion and damage of the flavor of contents.
[0005]
Further, in the invention described in Japanese Utility Model Publication No. 57-42818, in the push-down opening type can lid in which the opening portion formed in the center plate is closed by a tongue piece which is continuous with the center plate in a small portion, The boundary between the periphery of the opening portion and the periphery of the tongue piece is divided into a thin fragile portion, a break separation portion, and a cut separation portion sequentially from a small portion of the tongue piece, and the cut separation portion and the break separation portion on the opening start side are It has been completely broken.
[0006]
In the structure described in this Japanese Utility Model Publication No. 57-42818, a cutting / separating portion in which the boundary line is completely cut is provided at the boundary line serving as the opening start end located on the opposite side of the small portion. The pressing force required for opening can be small. Further, since the sealing agent is applied even when the boundary line is completely cut, the sealing property is maintained, the leakage of the contents is prevented, and at the same time, a protective function for replacing the damaged film can be produced.
[0007]
[Problems to be solved by the invention]
The cutting of the panel part by the score line or the boundary line is performed by pressing the score blade against the panel part and making a slit-like cut, and the score line is not cut off from the metal material forming the panel part. Alternatively, there is basically no substantial gap caused by the cutting of the panel portion by the boundary line. However, deformation may occur after the score line or boundary line is formed due to an external force that is not assumed when forming the score line or boundary line, or due to non-uniform quality of the metal material. Even if the ends are not flush with each other and no pressing force is applied, the broken portion may open. In addition, when the score line is formed in the folded portion, the molding becomes unstable and deformation is likely to occur as compared with the case where the score line is formed in the portion other than the folded portion.
[0008]
The occurrence of a gap due to such deformation is referred to as a mouth opening, and when a mouth opening occurs, at least one of them moves in the thickness direction without maintaining the state where the fracture ends face each other. Therefore, when the above-described sealant is applied, the sealant may leak to the surface side of the can lid (the outer surface side of the can). That is, from the sealing agent application process to the dryer through the conveyor, until the sealant is dried and cured, the sealant has fluidity, so it leaks from the gap in the mouth to the outer surface of the can lid, Appearance and appearance are impaired when it becomes visible from the outside. In addition, in combination with this, the amount of the sealant for closely contacting the fracture surfaces of the inner surfaces is reduced, and inconveniences such as poor adhesion are likely to occur.
[0009]
The present invention has been made with the above points as a background, and provides a can lid that does not leak the sealant applied to the inside of the can lid and can be easily opened with a small pressing force. It is intended.
[0010]
[Means and Actions for Solving the Problems]
In order to achieve the above object, according to the first aspect of the present invention, both ends are separated from each other by a predetermined distance from a flat portion in a panel portion in which a flange portion for winding is formed on the outer peripheral portion. The first opening piece is defined by the score line, and the portion between the end portions of the score line spaced apart from each other pushes the first opening piece into the can. connecting before SL flat portion suspended state to being a first hinge portion, further in the flat portion opening easily can lid sealing agent is applied to the back surface of the to conceal the score line, the first opening Chi sac said score lines are partitioned pieces, half of the region located opposite to the at least before Symbol first hinge part, breaks said score line is penetrated in the plate thickness direction of the flat portion is formed And the rupture portion is formed. During half of the region located opposite to the first hinge portion, the outer peripheral edge and the outer peripheral edge of the front Symbol first opening piece by the score line does not penetrate in the thickness direction of the flat portion An easy opening can lid characterized in that a locking portion is formed to engage with the inner peripheral edge of the flat portion facing each other so as not to be relatively deformed in the plate thickness direction.
[0011]
Therefore, according to the first aspect of the present invention, in the half region located on the side opposite to the first hinge portion, a break portion is formed by the score line penetrating in the plate thickness direction of the flat portion. , moreover portion thereof, since the most distant from the first hinge portion that connects the first opening piece to the flat portion, but called opening mentioned above it is likely to occur, along with a breaking portion breaks There are formed, in the half of the region located opposite to the first hinge portion, the engaging portion score line does not penetrate in the thickness direction of the flat portion of the panel portion is formed Thus, relative deformation in the plate thickness direction between the first opening piece and the flat portion is prevented. Therefore, the deformation of the first opening piece and the opening due to it do not occur.
[0012]
In addition to the invention of claim 1, the invention of claim 2, in addition to the invention of claim 1, is such that the locking portion is in a bilaterally symmetrical position with respect to a straight line connecting the first hinge portion and the center of the first opening piece. It is an easy-to-open can lid characterized by being formed.
[0013]
Therefore, according to the second aspect of the present invention, the relative deformation of the first opening piece relative to the flat portion is most likely to occur at the portion opposite to the first hinge with respect to the central portion, The first opening piece is supported so that the deformation is not caused by the latching portion formed at the sandwiched left-right symmetrical position. As a result, the relative deformation of the first opening piece and the mouth opening resulting therefrom are effectively prevented. Moreover, since the part on the opposite side to the first hinge part is a broken part penetrating in the plate thickness direction, the force required to push open the first opening piece may be small, and the lid opening property is not impaired. .
[0014]
Furthermore, in the invention of claim 3, in addition to the invention of claim 2, the locking portion is in a range of 25 ° to 90 ° in a direction away from the straight line with the center of the first opening piece as a center. It is an easy-to-open can lid.
[0015]
Therefore, according to the third aspect of the present invention, the direction apart from the straight line connecting the first hinge portion and the center of the first opening piece, specifically, the range of less than 25 ° in the forward and reverse directions is broken. Part. As a result, the opening of the mouth can be reliably prevented, and at the same time, the force required for the initial breaking for pushing and opening the first opening piece may be small, and the opening performance is improved.
[0016]
According to a fourth aspect of the present invention, in addition to any one of the first to third aspects of the present invention, the inner circumferential side of the first opening piece has a curved shape with both ends spaced apart and a pressing force. A substantially circular second opening piece defined by a breaking line that is broken by the above is provided, and the breaking line completely cuts the flat portion in the plate thickness direction except for the separated portions at both ends thereof. And the edge portion of the second opening piece is polymerized on the surface of the first opening piece on the inner surface side of the can, and the inner surface side of the overlapping portion is covered with a sealing agent and sealed. It is an easy-to-open can lid.
[0017]
Therefore, according to the invention described in claim 4, even when used in a so-called positive pressure can where the internal pressure of the can is high and the internal pressure of the can acts as a force that resists the pressing force of the first opening piece, Since the gas inside the can can be extracted by the two opening pieces and the internal pressure can be lowered, the first opening piece can be easily opened by pressing with a finger.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, specific examples of the present invention will be described with reference to the drawings. FIG. 1 shows a specific example of the present invention, in which an opening protruding can lid 1 and a can body 2 are shown. Opening protruding can lid 1 corresponding to the easy opening can lid of the present invention is formed of a flat plate material (not shown) made of metal such as aluminum alloy. Note that an inner film (not shown) made of synthetic resin is formed in advance on one surface of the flat plate. This inner surface film is formed from a protective paint or a resin film.
[0019]
The coating may be any protective coating made of a thermosetting or thermoplastic resin, for example, a modified epoxy coating such as a phenol-epoxy coating or amino-epoxy coating, a vinyl chloride-vinyl acetate copolymer, an epoxy-phenol modified vinyl coating. These are used alone or in combination of two or more, such as vinyl or modified vinyl paint. As the resin film, a polyester resin having ethylene-terephthalate as a basic component, for example, polyethylene terephthalate (PET), and further a copolymer such as polyethylene terephthalate-isophthalate (PET / I) can be applied. When a resin film is used for the inner surface coating, the resin film may be unstretched or biaxially stretched.
[0020]
On the outer peripheral side of the opening protruding can lid 1, a well-known flange portion 5 </ b> A is formed which is fastened and fixed to the opening end 4 of the cylindrical can body 3 to form the winding portion 5. Further, an annular groove 6 that is recessed substantially downward in FIG. 1 is formed on the inner side in the radial direction of the opening protruding can lid 1 from the tightening portion 5. The cross-sectional shape of the annular groove 6 in the axial direction of the can body 3 is a U-shape.
[0021]
A skirt wall 7 is formed extending from the annular groove 6 toward the central axis of the can body 3 and extending upward in FIG. The skirt wall 7 is curved in an arc shape in cross section. Further, a ridge 8 is formed following the upper end of the skirt wall 7 in FIG.
[0022]
Further, an upper neck portion of the raised portion 8 in FIG. 1 is formed with a mouth / neck portion 9 whose side wall surface slightly protrudes outward in the radial direction. That is, the mouth-and-neck portion 9 itself has a cylindrical shape with different outer diameters in the length direction. Note that the mouth and neck portion 9 is not limited to the above shape, and may be, for example, a cylindrical shape having a constant outer diameter, that is, a shape in which the side wall surface is substantially parallel to the central axis of the can body 3. A protruding portion 10 is formed by the mouth / neck portion 9, the skirt wall 7, and the raised portion 8.
[0023]
On the other hand, the wall surface connected to the upper edge portion of the mouth / neck portion 9 is bent toward the inner peripheral side. That is, a surface that closes the upper edge of the mouth-and-neck portion 9 is provided, and the surface is a flat surface that is substantially orthogonal to the central axis of the can body 3. This portion is formed as an annular flat portion 11.
[0024]
Further, the wall surface connected from the inner edge of the annular flat portion 11 is bent downward in FIG. 1 substantially parallel to the central axis of the can body 3, and this is formed as the inner peripheral wall 12. That is, the inner peripheral wall 12 is a wall surface having an annular shape as a whole provided on the inner peripheral side of the mouth and neck portion 9. Further, a recess 13 that is curved in an arc shape toward the lower side of FIG. 1 is formed at the lower edge of the inner peripheral wall 12. This hollow part 13 is formed over the whole circumferential direction, and has comprised the cyclic | annular form as a whole. The bottom part of this hollow part 13 is located below the lowermost layer 18 of the folding part 14 mentioned later.
[0025]
Furthermore, the wall surface on the inner peripheral side of the recess 13 is inclined upward toward the central axis, and this is the first annular wall 15. The wall surface connected from the upper edge of the first annular wall 15 forms a narrow flat surface perpendicular to the central axis of the can body 3, and a part of the flat surface forms a circular shape as a whole. It is folded into three layers, and this is formed as a folding portion 14.
[0026]
More specifically, the folding portion 14 has a structure in which a part of the flat surface is folded downward and radially outward, and the folded end is folded again toward the central axis of the can body 3. It has become. That is, as shown in FIG. 3, each layer (the uppermost layer 16, the intermediate layer 17, and the lowermost layer 18) in the folding portion 14 forms a flat surface and is orthogonal to the central axis of the opening protruding can lid 1. It is parallel to the line.
[0027]
The lowermost layer 18 in the folding portion 14 has both end portions of the score line 19 spaced apart by a predetermined interval, and a first opening piece 20 is defined on the inner peripheral side of the score line 19. Yes. Specifically, the score line 19 is formed along the fold portion 14, that is, outside the inner peripheral side distal end portion or the inner peripheral side bent portion of the fold portion 14, and is separated from both ends. A substantially circular shape is formed between the two. Therefore, the first opening piece 20 is a substantially circular member that is formed of a wall surface that is integrally connected to the lowermost layer 18 in the folding portion 14 and that is partitioned by the score line 19. As shown in FIG. 2, the first opening piece 20 has a portion between the two separated ends of the score line 19 as a first hinge portion 60, and the inside of the protruding portion 10 leaving the first hinge portion 60. It is a structure that can be suspended by being pushed down.
[0028]
More specifically, the first opening piece 20 is positioned at the same height as the lowermost layer 18 and has an outer flat portion 21 parallel to a line orthogonal to the central axis of the opening protruding can lid 1 and its outer side. A second annular wall 22 that is continuous with the inner peripheral edge of the flat portion 21 and is inclined upward, and an inner flat portion 23 that is continuous with the inner peripheral edge of the second annular wall 22 and parallel to the outer flat portion 21 are provided. . The inner flat portion 23 is provided at a position higher than the uppermost layer 16 of the folding portion 14 in the protruding direction of the protruding portion 10.
[0029]
Furthermore, as shown in FIG. 4, in the present embodiment, locking portions 70 are formed at two locations within the score line 19. The number of locations where the locking portions 70 are formed is not limited to two, and is determined in consideration of work efficiency, the effect of preventing deformation of the first opening piece 20 in the plate thickness direction, and the ability to open the lid. As an example, the place where the locking part 70 is formed is a straight line connecting the center of both ends of the first hinge part 60 and the substantially circular center formed by the score line 19, that is, the center of the first hinge part 60. When the straight line connecting the center of the first opening piece 20 is L, and the straight line connecting the center of the locking part 70 and the center of the first opening piece 20 is M, the first hinge part 60 is on the opposite side. It is a half region located, and is a position symmetrical to the straight line L where the angle θ formed by the straight line L and the straight line M is 30 °. The remaining portion of the first opening piece 20 is a broken portion 71 in which the score line 19 penetrates in the plate thickness direction.
[0030]
5A is a circumferential cross-sectional view of the score line 19, and FIG. 5B is a cross-sectional view of the score line 19 on the straight line M. In the present embodiment, the locking portion 70 is formed as a non-breaking portion in which the score line 19 does not penetrate in the plate thickness direction, and the shape thereof is the circumferential direction as shown in FIGS. The flat portion 70a has a width of 0.1 mm and a remaining thickness of 0.1 mm. However, the locking portion 70 is not limited to this shape. FIG. 5C is a plan view showing the locking portion 70 and the breaking portion 71 formed by the score line 19 from the inner side of the can lid. As shown in FIG. 5 (c), an inclined portion 70 b is formed between the flat portion 70 a and the fracture portion 71 of the locking portion 70, and the remaining thickness becomes thinner as it approaches the fracture portion 71. The position where the locking portion 70 is provided is preferably in the range where the angle between the straight line L and the straight line M (θ in FIG. 4) is 25 ° to 90 °, with the center of the first opening piece 20 being the center. If it is this range, the deformation | transformation prevention function to the plate | board thickness direction of the 1st opening piece 20 and the push-opening property (lid opening property) of the 1st opening piece 20 can be made compatible.
[0031]
6A is a cross-sectional view of the score blade in the circumferential direction, and FIG. 6B is a cross-sectional view of the score blade facing the straight line M. In order to form the locking portion 70, a score blade 100 as shown in FIG. 6A is used. In order to form the fracture | rupture part 71, a fracture | rupture is performed in the 1st part 100a. In order to form the flat portion 70a of the locking portion 70, the second portion 100b is used. In order to form the inclined portion 70b between the locking portion 70 and the breaking portion 71, the third portion 100c is used. The cross-sectional shape of the score blade 100 is a substantially trapezoidal cross section as shown in FIG. 6B, and the overall planar shape is a substantially circular shape as shown in FIG.
[0032]
In addition, the opening part which appears in the state which pushed down the 1st opening piece 20 is the 1st opening part 24, The internal diameter of the 1st opening part 24 is corresponded to the internal diameter of the folding part 14, and is 16 mm as an example. It is set above. This is a so-called lower limit of a value at which a beverage as a canned content can be easily poured.
[0033]
Further, a plastisol 25 as a sealant is applied to a portion of the first opening piece 20, the folded portion 14, and the first annular wall 15 adjacent to the score line 19. The plastisol 25 prevents the score line 19 from being broken by a change in the internal pressure of the can body 2 and repairs damage to the coating film due to the formation of the score line 19. This is to prevent corrosion. By applying the plastisol 25, leakage of the content liquid can be prevented.
[0034]
A protruding second opening piece 26 is provided on the inner peripheral side of the inner flat portion 23 in the first opening piece 20. Specifically, the second opening piece 26 is a substantially circular protrusion defined by the inner peripheral edge of the inner flat portion 23, and an annular flange portion 27 that is in close contact with the inner surface side of the inner flat portion 23, and the annular flange An inclined wall portion 28 that is continuous with the inner peripheral edge of the portion 27 and is inclined upward, and is continuous with the inner peripheral edge of the inclined wall portion 28 and parallel to a line orthogonal to the central axis of the opening protruding can lid 1. And a pressing portion 29. And the panel part 40 is formed of this 2nd opening piece 26, the 1st opening piece 20, and the hollow part 13. As shown in FIG.
[0035]
The outer diameter of the annular flange 27 is set to be slightly larger than the inner diameter of the inner flat portion 23 of the first opening piece 20, and the annular flange 27 is superimposed on the inner flat portion 23. The overlapping portion is formed as an overlap portion 50, and plastisol 30 is applied in the vicinity of the overlap portion 50. Specifically, the plastisol 30 is provided in a state in which the annular flange 27, the inner flat portion 23, and the second annular wall 22 are integrally covered, and the overlap portion 50 is sealed.
[0036]
Next, the formation and operation of the engaging portion 70 of the easy opening lid configured as described above will be described. When the score blade 100 for providing the score line 19 on the lowermost layer 18 is pressed, a substantially circular first opening piece 20 defined by the score line 19 is formed. At that time, the locking portion 70 is formed at a position 30 ° symmetrical to the straight line L connecting the center of both ends of the first hinge portion 60 and the substantially circular center formed by the score line 19. The first opening piece 20 is held by the first hinge part 60 and the locking part 70. That is, the locking portion 70 acts so that the outer peripheral edge of the first opening piece 20 and the inner peripheral edge of the lowermost layer 18 are opposed to each other, in other words, the relative deformation in the plate thickness direction does not occur. The first opening piece 20 is held.
[0037]
As a result, the opening (gap) is not generated by shifting in the thickness direction from the position where the outer peripheral edge of the first opening piece 20 and the inner peripheral edge of the lowermost layer 18 face each other. Next, plastisol 25 is applied to a portion adjacent to the score line 19. Since the plastisol 25 has no opening (gap) between the outer peripheral edge of the first opening piece 20 and the inner peripheral edge of the lowermost layer 18, the plastisol 25 stays in the vicinity of the score line 19 and may leak to the outer flat portion 21, which is the outer surface of the can lid. And the appearance of the can lid is not impaired. Further, since the plastisol 25 does not leak and decrease, the adhesion between the outer peripheral edge of the first opening piece 20 and the inner peripheral edge of the lowermost layer 18 can be sufficiently ensured. The inner peripheral edge of the lowermost layer 18 corresponds to the inner peripheral edge of the flat portion of claim 1.
[0038]
On the other hand, when opening the above can lid, first, the pressing portion 29 of the second opening piece 26 is pressed with, for example, a thumb. By pressing the pressing portion 29, a break along the break line 31 occurs, and the second opening piece 26 is pushed down to the inside of the opening protruding can lid 1. In that case, the second opening piece 26 is suspended by the second hinge portion 61. As a result, a gas such as carbon dioxide gas formed in the second opening 32 and enclosed in the can 2 is discharged to the outside. Then, a part of the thumb comes into contact with the inner flat portion 23, and the first opening piece 20 is pushed down into the can. In that case, since the score line in the portion on the opposite side to the first hinge portion 60 penetrates in the plate thickness direction and forms the fracture portion 71, the first opening piece 20 can be easily pushed open. That is, the force required for the initial break may be small. Thereafter, the deformation of the first opening piece 20 reaches the portion of the locking portion 70. At that time, the deformation of the first opening piece 20 has progressed, and this is applied to the locking portion 70. Since the tearing load acts, the locking portion 70 is easily broken.
[0039]
Finally, the first opening piece 20 is opened by the first hinge part 60 between the ends of the score line 19 in a state of being hung inside the opening protruding can lid 1. Furthermore, as shown in FIG. 2, since the position of the second hinge portion 61 coincides with the position of the first hinge portion 60 in the circumferential direction, the direction of the can body 2 or the direction of the finger for pressing is changed. It is not necessary.
[0041]
【The invention's effect】
As described above, according to the first aspect of the present invention, the score line penetrates in the thickness direction of the flat portion of the panel portion in the half region located on the opposite side to the first hinge portion. Since the rupture part is formed, and that part is farthest from the first hinge part connecting the first opening piece to the flat part, the so-called mouth opening described above is likely to occur, The score line does not penetrate in the thickness direction of the flat portion of the panel portion in the half region located on the opposite side to the first hinge portion, in which the broken portion is formed together with the broken portion have locking portion is formed, the relative deformation is prevented in the thickness direction of the first opening piece and the flat part, it is possible to reliably prevent the mouth opening caused deformation or to that of the first opening piece As a result, the sealant leaks to the outside or It is possible to prevent that the or impaired.
[0042]
According to the invention of claim 2, the relative deformation of the first opening piece with respect to the flat portion is most likely to occur at a portion opposite to the first hinge with respect to the central portion. The first opening piece is supported so that the deformation is not caused by the latching portion formed at the symmetrical position with the portion sandwiched therebetween, so that the relative deformation of the first opening piece and the mouth opening resulting therefrom In addition, since the portion on the opposite side of the first hinge portion is a broken portion cut by the score line, the force required to push open the first opening piece may be small, and the lid opening property Can be made good.
[0043]
Furthermore, according to the invention described in claim 3, the direction apart from the straight line connecting the first hinge portion and the center of the first opening piece, specifically, the range of less than 25 ° in the forward and reverse directions is broken. Since it becomes a part, opening of a mouth can be prevented reliably, and at the same time, the force required for initial breakage for pushing and opening the first opening piece may be small, and the lid opening property can be improved.
[0044]
Further, according to the invention described in claim 4, even when used in a so-called positive pressure can where the internal pressure of the can is high and the internal pressure of the can acts as a force that resists the pressing force of the first opening piece, Since the gas inside the can can be extracted by the two opening pieces and the internal pressure can be lowered, the first opening piece can be easily opened by pressing with a finger, and a can lid having a good openability can be obtained.
[Brief description of the drawings]
FIG. 1 is a schematic view showing a specific example of the present invention.
FIG. 2 is a schematic view showing an opening protrusion can lid from the pressing part side.
FIG. 3 is a cross-sectional view showing the vicinity of a score line and a break line.
FIG. 4 is a schematic view of a first opening piece formed by a score line.
5A and 5B are explanatory views showing the shape of the locking portion, where FIG. 5A is a circumferential sectional view of the locking portion, FIG. 5B is a sectional view of a folding portion including the locking portion, and FIG. It is a front view which shows the latching | locking part and fracture | rupture part which were formed with the score line from the can lid inner surface side.
6A and 6B are explanatory diagrams showing a score blade, wherein FIG. 6A is a side view of the score blade, and FIG. 6B is a cross-sectional view of the score blade.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Opening protrusion can lid, 19 ... Score line, 20 ... First opening piece, 21 ... Outer flat part, 23 ... Inner flat part, 25, 30 ... Plastisol, 26 ... Second opening piece, 29 ... Pressing part, 31 ... Break line, 32 ... Second opening, 40 ... Panel part, 50 ... Overlap part, 60 ... First hinge part, 70 ... Locking part.

Claims (4)

A first opening piece is defined by a score line in which both end portions are separated from each other at a predetermined interval on a flat portion of the panel portion in which a flange portion for tightening is formed on the outer peripheral portion. said first opening piece is a first hinge portion connecting the front SL flat portion in a state of suspended inside the can when the portion between the ends that are separated from each other down the said first opening piece inside the can In addition, in the easy opening can lid in which a sealing agent is applied to the back surface of the flat part so as to conceal the score line,
Chi sac said score lines are partitioning the first opening piece, the at least before Symbol first hinge half region located on the opposite side, the score line is penetrated in the plate thickness direction of the flat portion The score line penetrates in the plate thickness direction of the flat portion in a half region located on the side opposite to the first hinge portion where the fracture portion is formed and the fracture portion is formed. are engagement portion and the inner peripheral edge is engaged to prevent relative deformation in the thickness direction of the flat portion facing the outer peripheral edge and the outer peripheral edge of the front Symbol first opening piece formed by the absence An easy opening can lid characterized by that. 2. The easy opening can according to claim 1, wherein the locking portions are respectively formed at symmetrical positions with respect to a straight line connecting the first hinge portion and the center of the first opening piece. lid. The easy opening can lid according to claim 2, wherein the locking portion is formed in a range of 25 ° or more and 90 ° or less in a direction away from the straight line with the center of the first opening piece as a center. . On the inner peripheral side of the first opening piece, a substantially circular second opening piece is provided which has a curved shape with both ends separated and is broken by a breaking line that is broken by a pressing force. The flat part is completely cut in the plate thickness direction except for the part where the part is separated, and the edge part of the second opening piece is superposed on the surface which becomes the inner surface side of the first opening piece. 4. The easy-to-open can lid according to any one of claims 1 to 3, wherein the inner surface side of the superposed portion is covered and sealed with a sealant.

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