WO2019188612A1

WO2019188612A1 - Metal can

Info

Publication number: WO2019188612A1
Application number: PCT/JP2019/011565
Authority: WO
Inventors: 俊樹奥村; 野村　哲郎; 清澄眞仁田
Original assignee: 東洋製罐株式会社
Priority date: 2018-03-30
Filing date: 2019-03-19
Publication date: 2019-10-03
Also published as: JP7305921B2; JP2019177924A

Abstract

The present invention provides a metal can that has a polyhedron wall having high axial load strength. The metal can has a polyhedron wall with a structure in which unit panel columns obtained by arranging a plurality of unit panels in the direction parallel to the central axis of a can body are densely arranged all around the can body in the circumferential direction thereof, and a cross-section passing through a horizontal ridgeline of the unit panels has a polygonal shape. The metal can is characterized in that the shape of the cross-section passing through the horizontal ridgeline of the unit panels forms a polygonal shape having 14 or more corners, and the axial load strength is improved by increasing the number of corners.

Description

Metal can

The present invention relates to a metal can having a polyhedral wall constituted by a plurality of unit panels on a can body, for example.

As a conventional metal can having this type of polyhedral wall, for example, one described in Patent Document 1 is known.
In order to increase the rigidity of the can body, this metal can has a polyhedron wall in at least a part of the can body, and the polyhedron wall is a large number of unit panels having a folding structure partitioned into rhombus shapes by boundary ridge lines of the ridges. It is configured. This unit panel has a configuration in which unit panel rows arranged in a direction parallel to the central axis of the can body are densely arranged in the circumferential direction of the can body. It is molded into a regular polygon shape.
By providing a polyhedral wall with irregularities in this way, design characteristics were given, and the strength against the force in the direction perpendicular to the axis applied to the can body was increased, thereby reducing the thickness of the container. As for the strength against external pressure, it has been known that the strength decreases as the number of corners of the cross section passing through the horizontal ridge line of the unit panel increases, and has conventionally been set to 13 corners.

Japanese Patent No. 3915450

In recent years, metal cans tend to be thinner, and buckling deformation may occur in the winding process when the thickness is further reduced. Therefore, as a result of earnest research on the axial load strength of the metal can having the polyhedral wall, the present inventors have obtained the knowledge that the number of corners of the cross section passing through the lateral ridge line of the unit panel greatly affects the axial load strength. . The axial load strength is the buckling strength that causes buckling deformation when an axial compression load is applied.
An object of the present invention is to provide a metal can having a polyhedral wall with high axial load strength.

In order to achieve the above object, the present invention has a polyhedral wall composed of a number of unit panels defined by at least a part of a can body by convex boundary ridge lines,
The unit panel has a rhombus shape defined by the oblique ridgelines as the boundary ridgelines, two vertices located on a central plane passing through the central axis of the can body, and two vertices located symmetrically with respect to the central plane It has a total of four vertices, and has a valley fold horizontal ridge line connecting vertices located at symmetrical positions with respect to the center plane,
The polyhedral wall has a configuration in which a plurality of the unit panels are arranged in a direction parallel to the central axis of the can body, and the unit panel row is densely arranged in the circumferential direction of the can body. In the metal can where the cross section passing through the horizontal ridgeline is polygonal,
The cross-sectional shape passing through the horizontal ridgeline of the unit panel is a polygonal shape having 14 or more corners, and the axial load strength is increased by increasing the number of corners.
The present invention finds that the axial load strength of the can body is opposite to the strength in the direction perpendicular to the axis of the can body, and the strength increases as the number of cross-sections passing through the horizontal ridge line of the unit panel increases. To achieve a metal can with high axial load strength.

Further, the present invention can be configured as follows.
1) The number of corners of the cross section passing through the horizontal ridge line of the unit panel of the polyhedral wall is 26 or less.
When it becomes 26 corners, the axial load strength is almost the same as that of a straight can having no polyhedral wall, and it is not necessary to increase it further.
2) The protrusion amount at which the apex protrudes in the direction perpendicular to the axis from the extended surface of the straight portion of the can body that does not have the polyhedral wall is set to be 0.28 mm or less.
If the protruding amount is large, the apex is easily deformed when the cans or the can and the guide wall come into contact with each other during conveyance. The buckling is formed so that four unit panels surrounding the apex are depressed. If the apex is deformed, buckling is likely to occur. Therefore, it is preferable that the protrusion amount is small. However, because of the folding structure, the protrusion of the apex inevitably occurs, and the smaller the number of corners, the larger. If the angle is 14 or more, the amount of protrusion can be reduced, and a structure in which buckling does not occur as much as possible is obtained.

According to the present invention, the axial load strength can be increased by setting the cross-sectional shape in the direction perpendicular to the axis passing through the apex of the unit panel to a polygonal shape of 14 or more corners.

1A and 1B show a 14-corner metal can according to an embodiment of the present invention, in which FIG. 1A is a front view and FIG. 1B is a sectional view taken along line BB of FIG. 2A and 2B show the unit panel of FIG. 1, in which FIG. 2A is a front view and FIG. 2B is a cross-sectional view taken along the line CC of FIG. FIG. 3 shows a 16-corner metal can according to an embodiment of the present invention. (A) is a front view, (B) is a cross-sectional view taken along the line EE of (A), and (C) is a 26-corner. It is a front view of a metal can. 4A and 4B are diagrams showing a method for measuring the axial load strength, in which FIG. 4A is an overall view of the measuring apparatus, and FIG. 4B is a diagram showing a neck portion reinforcing jig used when measuring the axial load strength. FIG. 5 is a diagram showing the relationship between the number of corners of the horizontal cross section of the present invention and the conventional metal can and the axial load strength.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.
The dimensions, materials, shapes, and relative arrangements of the components described in this embodiment should be changed as appropriate according to the configuration of the apparatus to which the invention is applied and various conditions. The present invention is not intended to be limited to the following embodiments.
In the present invention, the horizontal cross-sectional shape passing through the horizontal ridge line of the unit panel is a polygonal shape of 14 or more corners, and the axial load strength is increased by increasing the number of corners. FIG. 3A and 3B show examples of 16 corners, and FIG. 3C shows examples of 26 corners.
Hereinafter, the basic configuration of the metal can will be described by taking the 14 corners as an example.
FIG. 1 shows a 14-corner metal can according to an embodiment of the present invention.
The metal can 1 includes a bottomed cylindrical can body 2 having a can body 21 and is an empty can before a lid is wound. A polyhedral wall 4 is provided on at least a part of the can body 21. The can body 2 has a configuration including a cylindrical can body 21 extending straight, a neck portion 22 with a reduced diameter at the upper end of the can body 21, and a bottom portion 23. A flange 24 around which the can lid is wound is provided.
In this embodiment, the metal can 1 is a squeezed iron can such as a general aluminum alloy, for example, a positive pressure can having an internal capacity of 250 to 500 ml and an internal pressure of 20 to 300 [kPa] at 5 ° C. In the metal can used, the thickness of the can body 21 is 0.08 to 0.20 [mm], the can body diameter D is 60 to 70 [mm] (211 diameter), and the can height H is 90 to 170. Use in the range of [mm] is assumed. The ratio of the can height H to the can body diameter D is about 1.3 to 2.6.
The present invention is not limited to the above metal cans for positive pressure cans, but can also be applied to negative pressure cans, and can be applied not only to aluminum alloys but also to steel cans and widely applicable to metal cans. It is.

The polyhedral wall 4 has a concave and convex shape by a folding structure without changing the circumference of the can body 21, and is composed of a large number of rhomboid unit panels 5 partitioned by the folds of the diagonal ridges 51.
That is, a predetermined number of unit panels 5 are arranged in a direction parallel to the central axis N of the can body 21 (hereinafter simply referred to as an axial direction) to form a panel row 50, and the panel row 50 is arranged in the circumferential direction of the can body 21. The configuration is arranged all around. The phase in the axial direction of the unit panels 5 of the panel rows 50 adjacent to each other is shifted by half the axial length of the unit panels 5 and the unit panels 5 are densely arranged in the axial direction and the circumferential direction. .
Since the adjacent panel rows 50 are displaced in the axial direction by half the length of the unit panel 5, the unit panels 5 of the panel rows 50 located every other circumferential direction are in the same phase in the axial direction, The horizontal ridge line 52 is connected via a common vertex 53. Therefore, the cross section cut in the direction perpendicular to the central axis N of the can body 21 at the position of the horizontal ridgeline 52 of the unit panel 5 has a regular polygonal shape as shown in FIG.
In this example, the polyhedral wall 4 is provided in a strip shape in the middle of the axial direction of the can body 21, and the upper and lower regions of the polyhedral wall 4 are cylindrical

straight portions

21 a and 21 b without irregularities.
The ratio (L / H) between the axial length L of the polyhedral wall 4 and the can height H is about 50%, and the length of the straight portion 21b on the bottom side is relative to the can height H. The ratio is about 19%, but other ratios may be used.

As shown in FIG. 2, the unit panel 5 includes two

vertices

53 a and 53 c located on a central plane M passing through the central axis N of the can body 21, and two vertices located at symmetrical positions with respect to the central plane M. It has a total of four vertices, 53b and 53d. These four vertices 53a to 53d are located on a cylindrical surface with the central axis N as the center, and a valley-folded horizontal ridgeline 52 connecting the

vertices

53b and 53d located in a symmetric position with respect to the central surface M is shown in FIG. As shown by the solid line in (B), it has a configuration in which it is bent and bent in the shape of a circle inward of the can body 21 in the axial direction. The diameter of the virtual cylindrical surface passing through the four vertices 53a to 53d is the maximum diameter of the can body 21.
In addition, the aspect ratio (b / a) between the length b between the

vertices

53a and 53c of the unit panel 5 (hereinafter, the length in the vertical direction) and the horizontal length a between the

vertices

53b and 53d is shown in the illustrated example. 1 is set to about 0.8 ≦ (b / a) ≦ 1.2, with 1 as the center, but a vertically long configuration may be set to about 0.8 ≦ (b / a) ≦ 2.0. .

The 16-corner form shown in FIGS. 3 (A) and 3 (B) and the 26-corner form shown in FIG. 3 (C) have the same basic configuration as the embodiment of FIG. 1, so only the differences will be described. The same components are denoted by the same reference numerals, and description thereof is omitted.
The difference is that the size of the unit panel decreases as the number of corners of the horizontal section increases. The height of the can body, the diameter of the can body, and the aspect ratio of the unit panel are all set to the same even if the number of corners changes, and the axial length of the polyhedron wall is almost the same. The number in the circumferential direction and the axial direction of the unit panel increases as the length decreases.
The number of unit panels is 28 in the circumferential direction, 28 in the circumferential direction, 4 in the axial direction and 3 in the axial direction, for a total of 98 planes, but in the 16 corner, the number of unit panels is 32 in the circumferential direction. In the five directions and four sides in the direction, a total of 144 planes and 26 corners, 52 planes in the circumferential direction, 8 planes and 7 planes in the axial direction every other row, a total of 390 planes.
The number of panels in the axial direction depends on how much the length L in the axial direction of the polyhedral wall 4 is taken. For example, in the case of a can having a can barrel diameter of 66.00 mm and a can height of 122.20, the axial length L of the polyhedral wall 4 is 64.70 mm at 16 angles and 61.60 mm at 26 angles.
Table 1 shows the relationship between the number of corners and the axial load strength. A straight can is a can that does not have a polyhedral wall in the can body.

The axial load strength was measured by preparing the following five types of aluminum cans as samples.
(Sample 1) Number of corners: 11 corners, horizontal length a (πD / n) of panel: 18.84 mm, ratio of polyhedral wall to can height (L / H): 54.0% (65.94 / 122.20), number of axial panels: 3 and 3
Here, n is the number of corners, D is the diameter of the can body, L is the length of the polyhedral wall in the axial direction, and H is the height of the can. The unit panel 5 has an aspect ratio (b / a) of 1, and L is equal to (the number of panels in the axial direction) × (the vertical length b of the panel). Since adjacent panel rows are shifted by a half phase, the number of panels in the axial direction is calculated as 3.5. Moreover, about the ratio (L / H) with the can height of the polyhedron wall, the second decimal point was rounded off to the first decimal place. The same applies hereinafter.
(Sample 2) Number of corners: 13 corners, horizontal length a (πD / n) of panel: 15.94 mm, ratio of polyhedral wall height to can (L / H): 52.2% (63.77 / 122.20), number of axial panels: 4 and 3, and L is (the larger number of panels (4)) × (the longitudinal length b of the panel).
(Sample 3) Number of corners: 16 corners, horizontal length a (πD / n) of panel: 12.95 mm, ratio with polyhedron wall can height (L / H): 53% (64.76 / 122) 20), number of axial panels: 5 and 4, L is (the larger number of panels (5)) × (the vertical length b of the panel).
(Sample 4) Number of corners: 26 corners, horizontal length a (πD / n) of panel: 7.97 mm, ratio of polyhedral wall to can height (L / H): 52.2% (63.77 / 122.20), number of axial panels: 8 and 7, L is (the larger number of panels (8)) × (the vertical length b of the panel).
(Sample 5) No polyhedral wall.
Each sample can is a can used for a 350 ml beverage can, and the dimensions are as follows.
・ Thickness of can body: 0.107 mm
・ Can body diameter (D): 66.00 mm (211 diameter)
・ Can height (H): 122.20mm
The plate thickness of the can body is the plate thickness at the position of the polyhedral wall. The can body diameter is the outer diameter of the straight portion.
Next, a method for measuring the axial load strength will be described.
An autograph (model number: AG-2000D) manufactured by “Shimadzu Corporation” was used as a measuring device for the axial load strength. First, the metal can 1 is placed on the pressure receiving table 61 of the measuring device 6 so that the flange 25 side faces upward, and the neck portion reinforcing jig 62 is placed on the opening of the metal can 1 as shown in FIG. Next, as shown in FIG. 4 (A), a compression load is applied to the neck portion reinforcing jig 62 placed on the metal can 1 at a compression speed of 10 mm / min using a test apparatus, the horizontal axis represents the compression amount, and the vertical axis To output a graph of compression load. When the buckling occurs, the compressive load decreases. Therefore, the maximum value of the graph is read and the value is set as the axial load strength. The measurement quantity is 12 cans or more, and the average value is obtained.

As shown in Table 1, the axial load strength was 923N for the 11th corner, 1173N for the 13th corner, 1458N for the 16th corner, 1582N for the 26th corner, and 1595N for the straight can without the polyhedral wall.
Basically, the compressive load in the axial direction is mainly supported by the oblique ridges 51. Therefore, when the number of corners increases, the number of oblique ridges 51 also increases, and the axial compressive load is dispersed to increase the axial load strength. The
FIG. 5 is a graph in which the axial load strength data in Table 1 is plotted with the number of angles on the horizontal axis and the axial load strength on the vertical axis.
According to this graph, the degree of increase in the axial load intensity is gentler in the gradient between the 16th and 26th corners than the gradient between the 11th and 13th corners. Looking at the ratio of the axial load strength of each corner to the straight can, from 16 to 26 corners, from 91% to 99%, an increase of 0.8% per corner, from 11 to 13 corners. In the corners, from 58% to 74%, with a 16% increment per corner, there is a large change with respect to the rate of change between the 16th and 26th corners.
In particular, the 13 corner is about 73.5% of the straight can, whereas the 16 corner is over 90%, and the 14 corner is an increment of 11 to 13 corners (8% per corner). ) Is 82%, almost 80%.
As shown in this result, according to the present embodiment, the axial load strength of about 80% or more of the straight can can be ensured by setting the horizontal cross section to 14 corners or more. Moreover, if it sets to 16 or more corners, about 90% or more of axial load intensity | strength of a straight can is securable.
On the other hand, when it is 26 corners, the axial load strength is almost the same as that of a straight can, and even more corners are meaningless in terms of increasing the axial load strength, and the workability also deteriorates. preferable.
Thus, according to the present invention, even if the plate thickness is reduced, the axial load strength is increased by making the cross-sectional shape in the direction perpendicular to the axis passing through the vertex 53 of the unit panel 5 into a polygonal shape of 14 or more corners. be able to. Further, in order to obtain a predetermined axial load strength, it is possible to reduce the plate thickness by increasing the number of corners of the horizontal section.

[Relationship between the number of corners of the polyhedral wall 4 and the protrusion amount with respect to the straight portion of the vertex]
Next, the amount of protrusion of the vertex 53 from the straight portion will be described with reference to FIG. In FIG. 2, subscripts a to d are attached to the reference numeral 53 in order to distinguish the top, bottom, left, and right vertices 53 of the unit panel 5. However, in the following description, there is no need to distinguish between them. The explanation will be made with the subscripts omitted.
The buckling occurs so that the four unit panels 5 surrounding the vertex 53 are recessed together around the vertex 53. The apex 53 has a chamfered shape in consideration of workability, but is inevitable with respect to the

straight portions

21a and 21b positioned above and below the polyhedral wall because it is positioned at the apex of the polygon of the horizontal section. Projecting outward. In the drawing, a two-dot chain line S is an extension line of the

straight portions

21a and 21b. When the apex 53 protrudes, for example, there is a possibility that the empty cans or the guide wall hits the guide wall during the conveyance, and the protrusion deforms, so that buckling deformation is promoted.
Therefore, it is preferable to make the protrusion amount δ as small as possible.
Table 2 shows the protrusion amount δ with respect to the

straight portions

21a and 21b with respect to the number of angles of the horizontal section of the polyhedral wall. In Table 2, the outermost diameter is the diameter of the cylindrical surface passing through the apex 53, and is calculated with calculated values including chamfering. For the 13th, 16th, and 26th angles, actual values are obtained to verify errors. .

As shown in Table 2, the protrusion amount δ is 13 corners, 0.33 mm at the maximum, gradually decreases as the number of corners increases, and 26 corners is 0.09 mm. The diameters of the

straight portions

21a and 21b are 66.00 mm. The protrusion amount δ is (outermost diameter−straight portion diameter) / 2. When actual dimensions were measured with respect to the calculated values, the error was ± 0.04 mm at the outermost diameter, and ± 0.02 mm at the protrusion amount on one side.
Thus, as the number of corners increases, the amount of protrusion decreases, so if it is set to 14 or more corners, it is smaller than the current 13 corners and is suppressed to the maximum (0.28 ± 0.02) mm, Even if the cans hit each other during conveyance, the impact of the collision can be absorbed by the

straight portions

21a and 21b. Therefore, deformation near the apex 53 can be prevented, and the decrease in the axial load can be minimized.
The data in Tables 1 and 2 and the graph in FIG. 5 are, in a specific example, an aluminum-based metal can with a can barrel thickness of 0.107 mm, a can barrel diameter (D) of 66.00 mm, and a can height. Although the point of increasing the axial load strength by setting the number of corners to 14 or more has been described for those having a length of 122.20 mm, the present invention is not limited to metal cans of these dimensions, In a metal can having a certain combination of plate thickness, can body diameter, and can height, the axial load strength can be increased by similarly setting the number of corners to 14 or more.

1 metal can,
2 Can body 21 Can body, 22 Neck part, 23 Bottom part, 24 Flange 4 Polyhedron wall 5 Unit panel 51 Diagonal ridge line, 52 Horizontal ridge line, 53 (53a to 53d) Vertex 50 Panel row 6 Measuring device 61 Pressure receiving table, 62 Neck part Reinforcement jig M Center plane N Center axis δ Projection amount

Claims

Having a polyhedral wall composed of a large number of unit panels partitioned by a convex boundary ridge line on at least a part of the can body;
The unit panel has a rhombus shape defined by the oblique ridgelines as the boundary ridgelines, two vertices located on a central plane passing through the central axis of the can body, and two vertices located symmetrically with respect to the central plane It has a total of four vertices, and has a valley fold horizontal ridge line connecting vertices located at symmetrical positions with respect to the center plane,
The polyhedral wall has a configuration in which a plurality of the unit panels are arranged in a direction parallel to the central axis of the can body, and the unit panel row is densely arranged in the circumferential direction of the can body. In the metal can where the cross section passing through the horizontal ridgeline is polygonal,
A metal can characterized in that the cross-sectional shape passing through the horizontal ridge line of the unit panel is a polygonal shape of 14 or more corners, and the axial load strength is increased by increasing the number of corners.
2. The metal can according to claim 1, wherein the number of corners of a cross section passing through a horizontal ridge line of the unit panel of the polyhedral wall is 26 or less.
2. The axial load strength when the cross-sectional shape passing through the horizontal ridge line of the unit panel is a polygonal shape of 14 or more is 80% or more of the axial load strength of a metal can having no polyhedral wall in the can body. Or the metal can as described in 2.
4. The projection amount of which the apex projects in the direction perpendicular to the axis from the extended surface of the straight portion not having the polyhedral wall in the can body is set to be 0.28 mm or less. 5. The metal can according to item 1.