JPS5833054Y2 - Metal can for internal pressure can formed by drawing and ironing process - Google Patents

Description

[Detailed description of the invention] This invention is a cylindrical metal wire (hereinafter referred to as a DI can) made by drawing and ironing and having an integrally formed bottom, which is used to create cans such as beer cans (hereinafter referred to as DI cans) that generate internal pressure. , referred to as an internal pressure can).

The can bottom of the DI can currently used as an internal pressure can has a shape in which the can bottom is hardly displaced by the can internal pressure, that is,
It is molded into a hemispherical shape that protrudes inward.

However, it is a condition that the can must be able to stand upright when transporting the can for purposes such as filling the can with liquid and sterilizing it, and when displaying the can.As long as this condition is met, the bottom of the can Based on the idea that it would be permissible for the DI can to be displaced toward the outside of the can due to the internal pressure of the can, a DI can that has a displaceable part at the bottom of the can has been developed (Japanese Patent Application Laid-Open No. 1983-1999).
127784).

A cross section of the bottom of this can is shown in FIG. Bottom 2 of this can
The cross-sectional shape of is sequentially from the line side part 1 toward the line axis XX,
First curved surface portion 3. Following this is a flat portion 4 which extends approximately perpendicular to the trunk and occupies 85-40% of the total area of the bottom 2. The second curved surface portion following it 5. and a hemispherical central portion 6 following it, among which a flat portion 4
can be displaced toward the outside of the can by the internal pressure of the can, but the central portion 6 is substantially unable to be displaced.

In this can, the flat part 4 is displaced (as shown by the two-dot chain line) due to the internal pressure of the can, but the central part 6 is not displaced, so the second curved part 5' after the displacement comes into contact with, for example, a desk surface. , the can can stand upright, and since the inner volume of the empty wire is increased in this can compared to the current can whose bottom is mostly hemispherical, the wire diameter or can height can be reduced by the amount of increase.
In addition, since the bottom of the can is allowed to bulge, the wall thickness can be made thinner compared to a hemispherical can bottom that does not allow bulge, and it is said that both can reduce the weight of the can by about 15%.

The present applicant has learned that the following methods can be used to reduce the weight of the can, in addition to increasing the internal volume of the empty wire as described above.

In other words, after the can is sealed, the bottom and the canopy are displaced toward the outside of the can in response to the internal pressure of the can, thereby increasing the internal volume of the can. The degree of decrease in the internal pressure of the can becomes large, and we found that if the degree of decrease in the internal pressure of the can becomes large, the condition of the can standing upright can be satisfied even if the bottom of the can and the canopy are made of thinner material than conventional materials. and filed a patent application based on it.

(Patent Application No. 5199296).

The present invention is a DI can which is an improved version of the can according to the above invention, and is characterized by a cylindrical metal can formed by drawing and ironing and having an integrally molded bottom.
In the cut plane cut along the plane including the line axis, from the body toward the line axis, the first curved surface part is a semicircle, the flat part extends in the direction perpendicular to the body, and the first curved part curves inward to the inside of the can. Formed by drawing and ironing, consisting of two curved parts, a rising part facing inside the can and in the direction of the wire axis, a third arc-shaped curved part that is convex toward the inside of the can, and a central part that is almost perpendicular to the wire axis and is flat. This is a metal can for internal pressure can.

An example of the present invention will be explained with reference to the drawings.

FIG. 2 is a partially cutaway front view of a DI can A according to the present invention, and FIG. 3 is an enlarged sectional view of the bottom of the can of FIG.

The can A consists of a body 11 and a bottom 12 integrally molded with the body, and the opening side end 13 of the body 11 is thicker than the center 14 that occupies most of the body. The side end portion 15 of the bottom portion 12 gradually increases in thickness as it faces downward, and is continuous with the bottom portion 12 having the same thickness as the material plate thickness.

Note that the curved surface portion 16 transitioning from the body portion 11 to the bottom portion 12 will be treated as being included in the bottom portion 12.

Thus, this curved surface portion 16 becomes a substantially semicircular first curved surface portion.

The can bottom of this specific example has this first curved surface portion 16 as the outermost peripheral portion of the bottom portion 12, and extends from this first curved surface portion 16 along the line axis Y-Y.
flat portions 17 extending perpendicularly to the line side portions 11 in order of direction. Continuous to the line axis side edge of the flat portion 17,
A second curved surface portion 18 that curves inward to the can, this second curved surface portion 18
Continuing from the rising part 1 towards the inside of the can and towards the line axis Y-Y direction
9. Continuing from the inner edge of this rising portion, a third arc-shaped curved surface portion 20.convex toward the inside of the can. and a substantially flat central portion 2 that continues from this third curved surface portion 20 and is substantially orthogonal to the line axis.
It consists of 3.

Here, the inside of the can and the outside of the can mean that the direction from the can bottom 12 toward the opening side of the can is the inside of the can, and the direction from the can bottom 12 in the opposite direction to the opening side is the outside of the can.

Since the can bottom of the DI can of the present invention has the structure as described above, the wall thicknesses of the can bottoms 2 and 12 are the same, the wire diameter d is the same, and the If the radius of curvature r1 of the curved surface portions 3 and 16 is the same, and the widths of the flat portions 4 and 17 are the same, the displaceable portions are the same, so the displacement of this portion due to the can internal pressure is the same. Although the central portion 6 of the can bottom 2, which is not shown in Figure 1, cannot be displaced toward the outside of the can, in the can of the present invention, the central portion 23 of the can bottom 12 is moved further toward the outside of the can than the edge of the can. Since the can can be displaced outward within a range that does not protrude, the amount of increase in the inner volume due to displacement due to the internal pressure of the can is greater in the can of the present invention than in the conventional can shown in Figure 1. That is clear.

This means that in the can of the present invention, the wall thickness at the bottom of the can is
This means that the wall thickness can be made thinner than the wall thickness at the bottom of the can as shown in the figure.

Therefore, the limit of the thickness of the wall at the bottom of the can is determined by the thickness of the central portion 23 when each of the portions 19, 20 and 23 forming the central portion 24 recessed toward the inside of the can is displaced by the internal pressure of the can. This is the thickness when a point 25 on the line axis coincides with a line 27 connecting the line axis side end 26 of the flat portion 17 displaced by can internal pressure.

This is because if it protrudes beyond this line 27, it will not be possible to stand upright.

Can A shown in Figures 2 and 3 has a thickness of 0.34 mm no H-1.
9 aluminum material (the can shown in Figure 1 is 0.355 mm
It is a cylindrical can with a diameter of about 55 mm manufactured by squeezing and squeezing a material with a thickness of The width l of the portion 17 is approximately 4.5 mm, the radius of curvature r2 of the second curved surface portion 18 is approximately 1.5 mm, the angle θ between the rising portion 19 and the line axis is approximately lO°, and the radius of curvature of the third curved portion 20 is approximately 1.5 mm, the depth hl from the bottom of the can to the apex 21 of the third curved surface portion 20 is approximately 6.0 mm, the depth h2 of the center point 22 of the central portion 23 is approximately 4 mm, and the third curved surface portion 20
and the center part are connected by a smooth curved surface.

This can A is made of a thinner material than the can shown in FIG.
The tube was sealed with a 30 mm thick aluminum easy-opening lid and sterilized, but the dose line maintained its shape so that it could stand upright.

As described above, according to the present invention, it is possible to use a thinner material than the bottom of the can shown in FIG.
When the width l of the flat portion 17 is narrowed, there is an effect that the upright stability of the can can be further improved compared to the case of the can shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the bottom of a known DI can having a displaceable portion at the bottom of the can. Figure 2 is a partially cutaway front view of an example of the metal can of the present invention;
The figure is an enlarged sectional view of the bottom of the can, which is missing in Figure 2. In the figure, A is a can, 11 is a body, 12 is a bottom, Y-Y is a line axis, 16 is a first curved surface, 17 is a flat portion extending in a direction perpendicular to the body, 18 is a second curved surface, 19 is the rising part, 2
0 is the third curved surface part, 23 is the flat central part.

Claims (1)

[Claims for Utility Model Registration] Shaped by drawing and ironing, has an integrally molded bottom, and on the bottom, in a cut plane cut along a plane including the wire axis, from the body to the wire axis side, approximately) A cylindrical metal wire having a first circular curved surface portion and a flat portion extending in a direction orthogonal to the body, following the flat portion, a second curved surface portion that curves toward the inside of the can, the inside of the can, and Molded by drawing and ironing, characterized by having a rising part facing in the direction of the line axis, a third arc-shaped curved part convex toward the inside of the can, and a substantially flat central part substantially perpendicular to the line axis. Metal can for internal pressure can.