JP2016084144A - Can end and can using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a can end which has the effect of preventing a seaming failure and the effect of preventing the appearance of a crack such as an annular groove part in a pressure test and which is excellent in pressure resistance, and a can using the can end.SOLUTION: In a can end 1, a circular curl part 2, a first curved part 3, a second curved part 4, a third curved part 5, a fourth curved part 6, a fifth curved part 7, an annular groove part 8 and a center panel part 14 are provided in order inward in a radial direction of a can body 1 from the radial outside of the can body in a longitudinal section.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a can end and a can using the same.

  As a typical can end shape that has been used in the past, there is a so-called full form end (FULLFORMEND). This can end has the advantage that it has a very good tightening property and has been widely used, but on the other hand, it has a drawback that the pressure resistance is low, and in order to secure a predetermined pressure resistance, it is a relatively thick end. It was somewhat disadvantageous economically because the material was used.

  On the other hand, a so-called Super End (registered trademark) proposed by Crown Co., Ltd. is widely used as a can end shape that can easily obtain a high withstand voltage and enables gauge down of the material (for example, Patent Document 1). reference). In this method, the position of the annular groove around the can end is brought closer to the inside in the radial direction than the conventional full form end, and the section connecting the end of the curled portion is linearly connected from the annular groove. It is. This method has an advantage that the gauge can be reduced as compared with the conventional full-form end because a high pressure strength can be obtained even if a material having the same thickness is used. However, on the other hand, 1) troubles such as leakage of the tightening part between the curl portion of the can end and the side wall of the can body (referred to as “winding failure”) are likely to occur. 2) The can end is inverted in the pressure test. When bent, there was a drawback that cracks were likely to occur in the annular groove of the can end.

  The disadvantage of the above 1) is that the section connecting the annular groove and the curl portion is straight, so that the wire length of the material is short, the slack is small, and the roll position during winding is slightly different. It depends on the shape being affected. In addition, the disadvantage of 2) is that the section connecting the annular groove and the curled portion is also linear, so the wire length of the material is short, the slack is small, and the material is excessive during reverse buckling in the pressure resistance test. This is because the tension acts.

  As a solution to the above-mentioned problems of the super end, a lightweight easy open end developed by Container Developments (CDL), and then further improved, the CDL container end plug (can end) proposed by Ball The shape design is also known (see Patent Document 2). In the container end plug (can end) shown in FIG. 4 of Patent Document 2, a lower chuck wall 10 (also referred to as a curved portion) and a circular end wall 4 connected to the upper end of a countersink 12 (also referred to as an annular groove). An outward projecting arch 30 (also referred to as a curved portion) that protrudes radially outward in a section connecting the upper chuck wall 8 (also referred to as a curved portion) extending downward and radially inward from (also referred to as a circular curled portion). This is different from the super end.

Japanese Patent No. 4280645 Japanese Patent No. 4388817

  The CDL can end shape described above has an improvement effect on the problems described in 1) and 2) above. However, providing one projecting outwardly projecting arch 30 (curved portion) radially outwards is not sufficient to prevent winding failure and crack generation during a pressure resistance test. In terms of strength, the CDL method has a problem that it is lower than the super end.

  An object of the invention is to provide a can end having an effect of preventing a winding failure and an effect of preventing the occurrence of cracks in an annular groove during a pressure test, and a can using the same, and a can using the same.

In order to achieve this object, the can end according to the first invention is:
The can end before being connected to the side wall of the can body, the can end in a longitudinal section from the radially outer side of the can body toward the radially inner side,
A circular curl for connecting to the side wall;
A first curved portion connected to the circular curl portion and extending downward and radially inward from the circular curl portion;
A second curved portion located radially at the lower end of the first curved portion and projecting radially outward;
A third curved portion located at the lower end of the second curved portion and projecting radially inward;
A fourth curved portion located at the lower end of the third curved portion and projecting radially outward;
A fifth curved portion extending downward and radially inward from the fourth curved portion;
An annular groove connected to the lower end of the fifth curved portion and projecting downward;
A center panel portion connected to the radially inner edge of the annular groove portion and formed in a disc shape;
It is a can end characterized by providing.

The can according to the second invention is
When the circular curl portion of the can end and the side wall of the can body according to the first invention are wound, the circular curl portion is bent and crimped to the side wall of the can body, and the first end of the can end is At least a part of the curved portion is pressure-bonded to a side wall of the can body, and at least a part of the first curved portion pressure-bonded to the side wall of the can body has a flat shape in a longitudinal section. .

As described above, the can end according to the present invention is
The can end before being connected to the side wall of the can body, the can end in a longitudinal section from the radially outer side of the can body toward the radially inner side,
A circular curl for connecting to the side wall;
A first curved portion connected to the circular curl portion and extending downward and radially inward from the circular curl portion;
A second curved portion located radially at the lower end of the first curved portion and projecting radially outward;
A third curved portion located at the lower end of the second curved portion and projecting radially inward;
A fourth curved portion located at the lower end of the third curved portion and projecting radially outward;
A fifth curved portion extending downward and radially inward from the fourth curved portion;
An annular groove connected to the lower end of the fifth curved portion and projecting downward;
Because it comprises a center panel portion connected to the radially inner edge of the annular groove portion and formed in a disk shape,
It is possible to provide a can end having an effect of preventing a winding failure and an effect of preventing the occurrence of cracks in an annular groove or the like at the time of a pressure test, and at the same time having an excellent pressure strength.

Moreover, the can according to the present invention is
When the circular curl portion of the can end and the side wall of the can body according to the present invention are wound, the circular curl portion is bent and crimped to the side wall of the can body, and the first curve of the can end At least a part of the portion is pressure-bonded to the side wall of the can body, and at least a part of the first curved portion pressure-bonded to the side wall of the can body has a flat vertical cross section,
It is possible to provide a can that has an effect of preventing a winding failure and an effect of preventing the occurrence of cracks in the annular groove portion of the can end at the time of a pressure test, and at the same time having an excellent pressure strength.

It is a partial schematic enlarged view of the longitudinal section of the can end of the embodiment of the present invention. It is explanatory drawing explaining in detail the curved part shown in FIG. It is the partial model enlarged view of the longitudinal cross-section of the structure where the can end and the side wall of the can main body were wound up. It is a comparison figure of the displacement amount S-action internal pressure P curve of the can end of this invention, and the can end of a comparative example (CDL system).

  The inventors of the present invention provide a can end that has an effect of preventing a winding failure and an effect of preventing cracks such as an annular groove during a pressure test, and at the same time, a can end using the same, and a can using the same. We studied earnestly what we can do.

  As a result, compared with a structure in which three curved portions are provided between a circular curled portion and an annular groove portion in a can end having the same plate thickness and the same diameter as in the conventional case (CDL method) can end. As in the can end of the present invention, a can end having all the effects can be obtained by adopting a structure in which five curved portions are provided between the circular curled portion and the annular groove portion (see FIG. 1 for details). I thought I could get a can.

  The found results are widely applied to can ends of cans with high internal pressure, such as beverage cans containing sparkling beverages such as carbonated drinks and beer, and beverage cans in which liquid nitrogen is dropped during filling of the contents. Applicable.

(Embodiment)
FIG. 1 is a partially schematic enlarged view of a longitudinal section of a can end according to an embodiment of the present invention, FIG. 2 is an explanatory view for explaining in detail the curved portion shown in FIG. 1, and FIG. It is the partial model enlarged view of the longitudinal cross-section of the structure fastened. In this embodiment, “radially outward” refers to a direction pointing to the outer edge of a can body (not shown), a circular curl portion described later or a seaming wall portion described later, and “radially inward” refers to The direction which points to the inside of a postscript can end, ie, the centermost part of a postscript center panel part. Further, the can end according to the present invention has, for example, an opening that is fastened and fixed to the opening end of the side wall of the bottomed can main body, and is capable of pouring the contents, and has a thickness of 0.23 mm. This is a steion tab type can end press-formed from an aluminum alloy plate or the like. Hereinafter, detailed description will be given with reference to the drawings.

  FIG. 1 is a partial schematic enlarged view of a longitudinal section of a can end 1 before being connected to a side wall 30 (see FIG. 3) of the can body (for example, being fastened and fastened), and is configured as follows. Yes.

In FIG. 1, the can end 1 has a longitudinal section in order from the radially outer side of the can body toward the radially inner side.
A circular curled portion 2 for connecting to the side wall 30;
A first curved portion 3 connected to the circular curled portion 2 and extending downward and radially inward from the circular curled portion 2;
A second curved portion 4 which is located at the lower end of the first curved portion 3 and protrudes radially outward;
A third bending portion 5 located at the lower end of the second bending portion 4 and projecting radially inward;
A fourth curved portion 6 located at the lower end of the third curved portion 5 and projecting radially outward;
A fifth curved portion 7 extending downward and radially inward from the fourth curved portion 6;
An annular groove 8 connected to the lower end of the fifth curved portion 7 and projecting downward;
A center panel portion 14 connected to the radially inner edge 17 of the annular groove portion 8 and formed in a disk shape. The uppermost end in the axial direction of the longitudinal direction of the can end 1 is the upper end portion 15, and the lowermost end is the lower end portion 16.

  The first bending portion 3, the second bending portion 4, the third bending portion 5, the fourth bending portion 6 and the fifth bending portion 7 constitute a chuck wall. In order to improve the pressure resistance performance of the can end 1, this chuck wall is formed when the internal pressure of the can abnormally rises and buckling (reverse buckling) occurs and the can end 1 is deformed to the outside of the can. The stress acting on the can end 1 is absorbed by the abnormally increased internal pressure. In the present invention, since the chuck wall is provided with the five curved portions 3, 4, 5, 6, and 7, the rigidity is further improved.

  The annular groove 8 is for reinforcing the pressure resistance at the can end 1, and an outer wall 9 connected to the lower end of the fifth curved portion 7, and an inner peripheral side of the outer wall 9. An inner wall portion 10 formed and a bottom portion 13 including an outer curved portion 11 and an inner curved portion 12 formed in a longitudinal section curved shape are provided. In the present invention, since the chuck wall is provided with the five curved portions 3, 4, 5, 6, and 7, the annular groove portion 8 can be positioned close to the inside in the radial direction, and as a result, the pressure resistance strength is large. improves.

In FIG. 2, an example of detailed specifications of each curved portion of the can end 1 shown in FIG. 1 will be described. Thickness of the can end 1 is 0.22 mm, the radius of curvature _{r 1} of the first bending portion 3 which is formed in the region A is 2.0 mm, the curvature of the second curved portion 4 which is formed in the region B the radius _{r 2} is 1.2 mm, the third radius of curvature _{r 3} of the curved portion 5 of 1.3 mm, the fourth radius of curvature _{r 4} of the curved portion 6 of which is formed in a region D 1.2 mm which is formed in the region C, the region the radius of curvature _{r 5} of the curved portion 7 of the 5 formed E is 1.3 mm. Further, the radii of curvature r ₆ and r ₇ of the outer curved portion 11 and the inner curved portion 12 are each 0.4 mm.

  FIG. 3 is a partial schematic enlarged view of a longitudinal section of the structure in which the can end 1 and the side wall 30 of the can body are wound together. In this figure, the circular curled portion 2 and the side wall 30 of the can body shown in FIG. And the circular curled portion 2 is bent into the cover hook portion 43 and the seaming wall portion 42 with the seaming panel portion 41 as a boundary, so that the can body body can be bent. While being crimped | bonded with the body hook part 31 of the side wall 30, at least one part of the 1st curved part 3 of the can end 1 is crimped | bonded with the side wall 30 of a can main body, and at least one part of the 1st curved part 3 is a longitudinal cross-section. A flat portion 51 having a flat shape is formed. Therefore, the flat part 51 is a to-be-compressed part, and the contact part 52 which closely_contact | adheres to the side wall 30 of a can main body is formed in a part among a series of curved parts mentioned above. In this way, a sealed can is completed.

  As shown in FIG. 3, when the can end 1 and the side wall 30 of the can main body are wound and fixed, the plurality of the above-described plurality provided in series from the lower end portion 16 of the annular groove portion 8 toward the outer peripheral side of the can end 1. Therefore, an excess wire length of the material, that is, a slack is secured, and an effect of preventing poor winding is obtained. . In addition, as shown in FIG. 3, when the can end 1 and the side wall 30 of the can main body are wound and fixed, the chuck wall has high rigidity, so that the internal pressure of the can rises abnormally and buckling ( Even when the can end 1 is deformed to the outside of the can due to the occurrence of reverse buckling, the deformation of the buckled portion called squaring deformation is alleviated and strain concentration is less likely to occur, and in addition, the excess lines of the above materials By ensuring the length, that is, the slackness, it is possible to prevent excessive tension from acting on the material, and the effect of preventing the occurrence of cracks in the annular groove portion 8 of the can end 1 can be obtained.

  Next, using a 5182 alloy aluminum plate with a thickness of 0.215 mm, assuming the case where the can end of the comparative example (shape corresponding to CDL) and the can end of the present invention are molded, analysis of their pressure strength is performed. went. The analysis was an elasto-plastic analysis using commercially available finite element analysis software, and axisymmetric elements were used. The 5182 alloy aluminum plate had the characteristics of a proof stress of 340 MPa and a tensile strength of 360 MPa. The end of the can was the same size as a commercially available beer can, and the outer diameter after winding was 57 mm. With the periphery of the can end fixed, deformation analysis was performed under boundary conditions in which pressure was applied to the inner surface of the can end, and the relationship between the internal pressure at the center of the can end and the amount of displacement was obtained (see FIG. 4).

  FIG. 4 shows the relationship between the working internal pressure P and the vertical displacement amount S of the central portion of the can end in the pressure resistance test. In FIG. 4, the can end of the present invention exhibited a higher working internal pressure P (that is, a higher pressure) with respect to the same displacement amount S than the can end of the comparative example.

(Applicable aluminum can)
The present invention is a two-piece all-aluminum can as a packaging container that is widely used for beverages and foods, and has a bottomed cylindrical body (also referred to as a can body or can body) whose bottom and side walls are integrated. It is suitable for a disc-shaped can end (also referred to as a can lid or a lid portion) which is sealed at the opening of the body and forms the upper surface.

  In this case, an AA to JIS3000 (Al-Mn) aluminum alloy plate is used for the body, but an AA to JIS5000 (Al-Mg) aluminum alloy plate is used for the can end. General purpose.

  The important characteristics required for aluminum alloy plates for can ends are: mold endurance that can withstand can end (can lid) processing, pressure resistance that can withstand the internal pressure of cans after filling beverages, and the end of the can (normally and easily) Can openability for opening the can lid). Furthermore, since it is required to reduce the cost of the can and reduce the plate thickness to 0.2 mm, the 5000 series aluminum alloy plate is preferable for these can ends (can lids).

(Preparation method of aluminum can end)
An example of a known method for producing a can end from an aluminum alloy plate (cold rolled plate) as a material will be described below.

  A blank material obtained by punching an aluminum alloy plate (pre-coated plate) as a pre-painted material into a disc shape (blanking material) is drawn with a press machine, and as shown in FIGS. 2 and the chuck wall are processed, and then a sealing compound is applied to the circular curled portion 2 to form an axisymmetric shell. Furthermore, rivet forming is performed by a press to form a convex portion for attaching a tab to the center of the shell. This rivet molding is a bubble molding process in which the central part of the can end 1 is projected, and a button molding in which the projecting part (bubble) obtained by this bubble molding is reduced in diameter in 1 to 3 steps to make a sharp projection. And a stake step in which the tab is crushed after the tab is assembled to the projection (button).

  After this, a die having a V-shaped cutting edge is pressed to form a groove in the drinking part, and irregularities and letters for increasing the rigidity of the center panel part 14 are formed, and an aluminum plate for a tab is separately provided. Molded and processed into a tab shape, and the tab is crimped and integrated with the convex portion processed at the center of the shell. And after baking (baking) of the coating film on this can end 1, it is separately DI-molded and wound around the side wall 30 which is an opening of an aluminum alloy body filled with contents (beverage, food) from the opening. Fastened and sealed as shown in FIG.

DESCRIPTION OF SYMBOLS 1 Can end 2 Circular curl part 3 1st curved part 4 2nd curved part 5 3rd curved part 6 4th curved part 7 5th curved part 8 annular groove part 9 outer side wall part 10 inner side wall part 11 outer side Bending portion 12 Inner bending portion 13 Bottom portion 14 Center panel portion 15 Upper end portion 16 Lower end portion 17 Radial inner edge 30 of annular groove portion 8 Can body side wall 31 Body hook portion 41 Seaming panel portion 42 Seaming wall portion 43 Cover hook portion 51 Flat part 52 Contact part

Claims (2)

The can end before being connected to the side wall of the can body, the can end in a longitudinal section from the radially outer side of the can body toward the radially inner side,
A circular curl for connecting to the side wall;
A first curved portion connected to the circular curl portion and extending downward and radially inward from the circular curl portion;
A second curved portion located radially at the lower end of the first curved portion and projecting radially outward;
A third curved portion located at the lower end of the second curved portion and projecting radially inward;
A fourth curved portion located at the lower end of the third curved portion and projecting radially outward;
A fifth curved portion extending downward and radially inward from the fourth curved portion;
An annular groove connected to the lower end of the fifth curved portion and projecting downward;
A center panel portion connected to the radially inner edge of the annular groove portion and formed in a disc shape;
Can end characterized by comprising. The circular curl portion of the can end according to claim 1 and the side wall of the can body are wound together, whereby the circular curl portion is bent and crimped to the side wall of the can body, and the first end of the can end. At least a part of the curved portion of the can is crimped to a side wall of the can body, and at least a part of the first curved portion crimped to the side wall of the can body has a flat vertical cross section.

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