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JP-2026074606-A - can

JP2026074606AJP 2026074606 AJP2026074606 AJP 2026074606AJP-2026074606-A

Abstract

[Problem] To provide a can that is lightweight and has excellent pressure resistance. [Solution] The outer diameter is 65.0 mm or more and 67.0 mm or less, the thickness of the center of the dome is 0.220 mm or more and 0.250 mm or less, the depth of the center of the dome is 10.65 mm or more and 13.50 mm or less, the radius of curvature of the outer surface of the dome is a single radius of curvature of 35 mm or more and 55 mm or less, the diameter of the contact point at the ground contact portion is 46.5 mm or more and 47.8 mm or less, the spreading angle at the point where the extensions of each counter portion facing radially intersect in any longitudinal section passing through the can axis is greater than 0° and 16° or less, the upper end of the counter portion and the outer edge of the dome portion are connected by a concave bend, the radius of curvature of the outer surface of the concave bend is 1.0 mm or more and 3.0 mm or less, and the heel portion is made up of multiple concave curved portions connected together, the radius of curvature of the outer surface of these concave curved portions increases as they move radially outward. [Selection Diagram] Figure 2

Inventors

  • 三枝 和也
  • 諏訪 浩朗

Assignees

  • アルテミラ・ホールディングス株式会社
  • アルテミラ製缶株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (5)

  1. An aluminum can having a cylindrical can body with an outer diameter of 65.0 mm or more and 67.0 mm or less, a bottom provided at one end of the body, a grounding portion that protrudes annularly outward in the direction of the can axis, a heel portion provided radially outside the grounding portion and connecting the can body and the grounding portion, a counter portion connected to the inner periphery of the grounding portion and inclined in a direction of decreasing diameter from below to above with respect to the direction of the can axis, and a dome portion provided radially inside the counter portion and recessed inward in the direction of the can axis, A can characterized in that the thickness of the central part of the dome is 0.220 mm or more and 0.250 mm or less, the depth of the central part of the dome is 10.65 mm or more and 13.50 mm or less, the radius of curvature of the outer surface of the dome is a single radius of curvature of 35 mm or more and 55 mm or less, the diameter of the contact point in the grounding part is 46.5 mm or more and 47.8 mm or less, the spreading angle at the point where the extensions of each counter part facing radially intersect in any longitudinal section passing through the can axis is greater than 0° and 16° or less, the upper end of the counter part and the outer edge of the dome are connected by a concave bend, the radius of curvature of the outer surface of the concave bend is 1.0 mm or more and 3.0 mm or less, and the heel part is made up of a plurality of connected concave curved parts, the radius of curvature of the outer surface of these concave curved parts increases as they move radially outward.
  2. The can according to claim 1, characterized in that the concave curved portion is formed by a first concave curved portion, a second concave curved portion, and a third concave curved portion from the ground contact side, and the radii of curvature of their outer surfaces are 1.5 mm to 9.0 mm for the first concave curved portion, 5.5 mm to 27.0 mm for the second concave curved portion, and 18.0 mm to 40.0 mm for the third concave curved portion.
  3. The can according to claim 1 or 2, characterized in that the contact portion has an inner bent portion formed convexly radially inward from its apex, and an outer bent portion formed convexly radially outward from its apex, wherein the radius of curvature of the outer surface of the inner bent portion is 0.8 mm or more and 1.75 mm or less, and the radius of curvature of the outer surface of the outer bent portion is greater than the radius of curvature of the inner bent portion, and is 1.0 mm or more and 3.0 mm or less.
  4. The can according to claim 1 or 2, characterized in that the radius of curvature of the outer surface of the convex curved portion between the outer edge of the heel portion and the lower end of the can body portion is 2.5 mm or more and 4.0 mm or less.
  5. The can according to claim 1, characterized in that the weight of the constituent metal is 9.9 g or more and 10.5 g or less.

Description

This invention relates to a metal can in which beverages and other contents are filled. Aluminum cans capable of containing beverages, food, and other contents include two-piece cans consisting of a can body with integrally molded side walls and bottom, and a can lid that is double-sealed and joined to the can body. The DI molding method is known as a manufacturing method for such cans. In this DI molding process, a pre-formed large-diameter, shallow cup is subjected to drawing and ironing, and a bottom portion is integrally formed at one end of the cylindrical can body. This bottom portion has a ground portion that protrudes annularly outward in the can axis direction, a heel portion that connects to the can body outside the ground portion, and a dome portion that is recessed inward in the can axis direction inside the ground portion. Subsequently, necking, flange processing, etc., are performed on the open end according to the final can shape, but the bottom portion formed by DI molding remains almost unchanged as the final shape of the product. In the case of such cans, the thickness of the can material is reduced (thinning) from the perspective of cost reduction and weight reduction. However, simply reducing the thickness of the can material leads to a decrease in strength. Patent Document 1 discloses a can in which the dome portion of the can bottom is shaped by connecting multiple curves with different radii of curvature, arranged so that the radii of curvature decrease sequentially as they extend radially outward from the can axis. The connection point between the radially inward curve with the largest radius of curvature and the curve connected to it is positioned at a location between 0.15L and 0.50L radially outward from the can axis, where L is the radial distance from the can axis to the ground. The thickness of the can bottom is, for example, 0.290 mm. This can is described as being able to improve the strength of the can bottom without increasing the plate thickness by shaping the dome portion by connecting multiple curves, and effectively preventing buckling. On the other hand, Patent Document 2 discloses a thin-walled DI can body with an outer diameter of 65 mm or more, a heel height of 10 to 13 mm, and a dome diameter of 46 to 48 mm. The can bottom cross-sectional shape is characterized by a radius of curvature of 1.8 to 2.2 mm and a central angle of 70 to 80° on the outer side of the contact area, a radius of curvature of 4.8 to 6.0 mm and a central angle of 70° or less on the heel body side, and a radius of curvature of 8 mm or more in the center of the heel. The can bottom wall thickness is, for example, 0.26 to 0.27 mm. It is stated that by using a can with this shape, a can bottom shape that can withstand axial loads, has excellent pressure resistance, and suppresses reduction in internal volume can be obtained. Japanese Patent Publication No. 2015-214343Japanese Patent Application Publication No. 8-48330 This is a front view showing a can that is an embodiment of the present invention, with a portion of it in cross-section.This is an enlarged cross-sectional view of the bottom of the can shown in Figure 1, showing half the diameter from the can axis.These are cross-sectional views showing the cup and cylindrical body formed during the manufacturing process of the can, in the order of (a) and (b).This is a cross-sectional view showing a part of the mold used to form a cylindrical body from a cup.This is a cross-sectional view showing a portion of the mold used to form the bottom. Embodiments of the present invention will be described below with reference to the drawings. The can in this embodiment is, as shown in Figure 1, a bottomed cylindrical can 1 made of, for example, aluminum or an aluminum alloy. Furthermore, this can 1 is used as a so-called two-piece can (stay-on tab can), which is sealed by filling the inside with contents such as a beverage and then attaching a can lid (not shown) to the open end. As shown in Figure 1, the can 1 is made of a thin sheet of aluminum (aluminum or aluminum alloy) and has a cylindrical can body 20 and a bottom 30 provided at one end of the can body 20. The can body 20 also has a shoulder 21 that gradually decreases in diameter towards the top, a small-diameter neck 22 formed at the upper end of the shoulder 21, and a flange 23 that extends radially outward at the upper end of the neck 22. Furthermore, the diameter (outer diameter) D1 of the can body 20 is set within the range of 65.0 mm to 67.0 mm (for example, 66 mm), and the overall height H0 of the can is set within the range of 122 mm to 124 mm. The opening diameter is commonly known as the 204 diameter. This opening diameter may also be 206, 202, or 200 diameter. The bottom portion 30 is provided with a grounding portion 31 that protrudes in an annular shape around the can axis S1 in the direction of the can axis S1 outward (downward in Figures 1 and 2), a heel portion 32 provided radially o