JP-7857093-B2 - can body

JP7857093B2JP 7857093 B2JP7857093 B2JP 7857093B2JP-7857093-B2

Inventors

小林智一
福本隼人
中村友彦
神山昂大

Assignees

東洋製罐株式会社
東洋製罐グループホールディングス株式会社

Dates

Publication Date: 20260512
Application Date: 20211209

Claims (4)

A bottomed cylindrical aluminum alloy can body having a can bottom and a cylindrical can body centered on the can axis, extending from the outer circumference of the can bottom along the can axis, The can bottom has a dome portion provided in the center of the can bottom, and an annular projection that is continuous with the outer edge of the dome portion and protrudes annularly outward from the can body along the can axis, The thickness of the aluminum alloy on the can shaft in the dome portion is 0.18 to 0.26 mm. The aforementioned annular protrusion is, A recess portion is provided continuously with the dome portion and has a curved surface that protrudes radially outward from the can body, The grounding portion that supports the aforementioned can body, Including the inner circumferential wall portion extending from the ground contact portion to the recess portion, The ground contact portion has a first convex curved surface on the side closer to the can axis and a second convex curved surface on the side further from the can axis, with the portion that protrudes most in the downward direction toward the can axis in the ground contact portion being sandwiched between them. The inner circumferential wall portion has an inclined surface, The outer diameter of the can body is within the range of 50 mm to 59 mm in diameter. The height of the can from the ground portion to the upper end of the can body is within the range of 120 mm to 190 mm. In a longitudinal cross-sectional view including the can shaft, The recess depth is 0.5 mm or more and 0.9 mm or less. The grounding diameter is φ44.0 mm or more and 47.0 mm or less. The radius of curvature of the first convex curved surface is 0.4 mm or more and 0.7 mm or less. The radius of curvature of the second convex curved surface is 1.6 mm or more and 2.2 mm or less. A can body in which the angle between the inclined surface on the inner circumferential wall and the can axis is 15° or more and 30° or less. Here, the recess depth is the radial distance between the part of the outer surface of the can body in the recess that is furthest from the can axis and the part of the outer surface of the can body in the grounding portion that is closest to the can axis, and the grounding diameter is the diameter of the part of the grounding portion that protrudes most downward in the direction of the can axis.
The radius of curvature of the recess is 0.3 mm or more and 1.2 mm or less. The can body according to claim 1, wherein the distance in the can axis direction from the portion of the contact area that protrudes most downward in the can axis direction to the portion of the outer surface of the can body in the recess that is furthest from the can axis is 1 mm or more and 4 mm or less.
The aforementioned dome section is The can body according to claim 1 or claim 2 , comprising a tapered portion having one end continuous with the outer periphery of the dome portion and the other end continuous with the recess portion.
The can body according to any one of claims 1 to 3, wherein the dome portion includes a first dome that is recessed inward along the can axis in the central part of the can bottom, and a second dome that is continuously provided radially outward on the outer edge of the first dome, recessed inward on the can body, and having a smaller radius of curvature than the first dome.

Description

This invention relates to a can body, and more particularly to a can body in which the bottom of the can has been refurbished. Conventionally, aluminum alloy cans (two-piece cans) are known as containers for filling beverages and other contents. The can body of an aluminum alloy can is obtained by punching a circular shape out of an aluminum alloy sheet, drawing it to form a shallow, bottomed cylindrical cup component, and then re-drawing and ironing the cup component to integrally form the can bottom and can body. In such cans, there is a demand for thinner can body thickness from a resource conservation perspective. In particular, when the contents are carbonated beverages, the can bottom is designed to ensure sufficient pressure resistance even with a thinned can. Specifically, the can bottom has a dome-shaped section that is recessed inward in the center, and an annular protrusion around the dome. Bottom reforming is then applied to the annular protrusion to ensure pressure resistance despite the thinning (for example, Patent Document 1). Furthermore, such cans are required to have sufficient drop resistance against impact from drops for distribution in the market (for example, Patent Document 2). Japanese Patent Publication No. 2000-190961U.S. Patent No. 7740148China Utility Model Registration No. 203903013 Specification This is a longitudinal cross-section of the can body along its axis.Figure 1 is a partially enlarged cross-sectional view of the bottom of the can body shown.This is an enlarged cross-sectional view of the bottom of a can according to a modified example 1 of an aluminum alloy can made by drawing and ironing according to an embodiment of the present invention.This is an enlarged cross-sectional view of the bottom of a can according to a modified example 1 of an aluminum alloy can made by drawing and ironing according to an embodiment of the present invention.This table shows the test results of dropping aluminum alloy cans with varying contact diameters, illustrating examples and comparative examples of the aluminum alloy cans according to the embodiment of the present invention.This table shows the test results of dropping aluminum alloy cans with varying recess depths, illustrating examples and comparative examples of the aluminum alloy cans according to the embodiment of the present invention. The embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, the same reference numerals indicate parts with the same function, and redundant explanations in each figure will be omitted as appropriate. Figure 1 is a longitudinal cross-sectional view of the can body 10 along the can axis O, showing a schematic representation of the can body 10. Note that in Figure 1, the cross-sectional shape is shown as a line diagram, omitting the description of the plate thickness of the can body 10. As shown in Figure 1, the can body 10 is formed in a bottomed cylindrical shape, having a can bottom 11 and a cylindrical can body 12 centered on the can axis O, which extends from the outer circumference of the can bottom 11 along the can axis O. The can bottom 11 comprises a dome portion 111 and an annular projection 112. The dome portion 111 is located in the center of the can bottom 11, and the annular projection 112 is continuous with the outer peripheral edge of the dome portion 111 and protrudes annularly outward from the can body 10 along the direction of the can axis O, supporting the can body 10. The annular projection 112 is provided continuously with the dome portion 111 and has a recess portion 112A having a curved surface that protrudes radially outward from the can body 10, a grounding portion 112B that supports the can body 10, and an inner circumferential wall portion 112C extending from the grounding portion 112B to the recess portion 112A (see Figure 2). (Embodiment) An embodiment of the present invention is, for example, a can made of aluminum alloy by drawing and twisting. The can body according to this embodiment is a pressed and ironed aluminum alloy can, and has the same configuration as the can body 10 shown in Figure 1, with the shape and dimensions of each part optimized. Therefore, the shape and dimensions of the can body 10 as a pressed and ironed aluminum alloy can according to this embodiment will be described below with reference to Figure 1. The can body 10, as a drawn and ironed aluminum alloy can, is obtained, for example, by punching a circular shape out of an aluminum alloy sheet, forming it into a bottomed cylindrical cup member by drawing, then re-drawing and ironing the cup member to integrally form the can bottom 11 and the can body 12, and finally trimming, necking, and flangeping the open end of the can body 12. The can body 10 has a can bottom 11 and a cylindrical can body 12 that extends from the outer circumference of the can bottom 11 along the can axis O, with the can bottom 11 and can body