WO2017187899A1

WO2017187899A1 - Can and method for forming curled section in can mouth

Info

Publication number: WO2017187899A1
Application number: PCT/JP2017/013904
Authority: WO
Inventors: 長谷川　俊幸; 政臣田村; 中村　友彦; 武志藍原; 健村瀬; 尚也松本
Original assignee: 東洋製罐株式会社
Priority date: 2016-04-27
Filing date: 2017-04-03
Publication date: 2017-11-02
Also published as: TW201738013A; JP7363870B2; JP2021185100A; JP6946620B2; JP2017197222A

Abstract

The present invention is a shape for a curled section whereby sealing performance desired for adhesion thereto by a cap can be obtained, and whereby deformation of the curled section by dropping impact is suppressed. A curled section 10 of a can 1 has: a top-end curved section 11 including the top end of a mouth 1D; an outer wall curved section 12, a bottom end 12A of which approaches or comes in contact with a side wall 2 of the mouth 1D, and an upper portion of which is inclined outward with respect to a can axis; an inside connecting curved section 13 having a smaller curvature radius than the curvature radius of the top end curved section 11, the inside connecting curved section 13 being provided on the inside of the top end curved section 11; and an outside connecting curved section 14 having a curvature radius smaller than the curvature radius of the top end curved section 11, the outside connecting curved section 14 being provided on the outside of the top end curved section 11.

Description

Can body and method of forming curl portion of can body mouth

The present invention relates to a can body and a method for forming a curl portion of a can body mouth portion.

A can body having a mouth portion is generally used as a container for a liquid container such as drinking water, and a curled portion in which an opening end is wound into a curl shape is formed in the mouth portion sealed with a cap. . In particular, the bottle can is formed by forming a metal plate made of aluminum or its alloy into a bottomed cylindrical body by drawing and ironing, and then performing neck-in processing on the opening of the bottomed cylindrical body. A reduced-diameter mouth portion is formed, and the mouth portion is subjected to a screw forming process and a curl forming process.

Various types of processing shapes have been proposed for the curl portion formed at the mouth portion of such a can in consideration of the sealing performance with the sealing material of the cap attached to the mouth portion.

For example, in the prior art described in Patent Document 1 below, the outer surface side wall portion in which the curled portion formed by folding the periphery of the opening portion radially outward extends in a direction substantially parallel to the can axis direction of the bottle can. And an outer surface side curved portion extending radially inward from the upper end of the outer surface side wall portion, and an inner surface side convex curved portion further extending radially inward from the outer surface side curved portion, the outer surface side wall portion having a predetermined length or more. In addition, the connection part between the outer side wall part and the outer side convex curved part that are linearly formed by crushing is formed in a shape separated from the upper end (upper end of the mouth part) of the bottle can. Yes.

In addition, the prior art described in Patent Document 2 described below is such that the outer curled portion is not subjected to curl crushing processing so that the outer surface is a curved surface protruding outward, and the longitudinal sectional shape of the curled portion is Is formed so as to be a vertically long oval.

JP 2004-217305 A JP 2006-188279 A

In the prior art described in Patent Document 1 described above, the curled portion is formed by a combination of curved flange processing (spinning molding) and linear crushing processing. At this time, the lower end of the outer surface side wall portion formed by the linear crushing process is a free end, and a relatively large gap is formed between the outer peripheral surface of the mouth portion (base portion) of the bottle can. . According to such a conventional technique, when a drop impact is applied in a state where the cap is sealed with a cap after the can is filled, the gap between the lower end of the outer side wall and the outer peripheral surface of the mouth is determined. As a result, the curled portion is deformed, and this deformation may cause a problem that a desired sealing property cannot be obtained at the seal point.

On the other hand, the conventional technique described in Patent Document 2 described above forms a curled portion that is entirely curved without being crushed, and the lower end of the curled portion is brought close to the outer peripheral surface of the mouth portion. Yes. However, the curled portion whose cross-sectional shape is a vertically long oval shape is not a shape that is resistant to drop impact, so the mouth is sealed with a cap after filling the can with the contents. When a drop impact is applied in this state, the curled portion is deformed so that the cross-sectional shape is crushed, and this deformation may cause a problem that a desired sealing performance cannot be obtained.

An object of the present invention is to eliminate such problems of the prior art, and has a curled shape that can obtain a desired sealing performance against a cap, It is an object of the present invention to suppress the deformation of the curled portion against an impact.

In order to solve such a problem, the can according to the present invention has the following configuration.
A can body having a mouth portion and having a curled portion at an opening end of the mouth portion, wherein the curled portion includes an upper end curved portion including an upper end of the mouth portion, and a lower end close to a side wall of the mouth portion. Or an outer wall curved portion that is in contact with and is inclined outward with respect to the can axis, an inner connecting curved portion that is provided inside the upper end curved portion and has a radius of curvature smaller than that of the upper end curved portion, and A can body comprising an outer connecting curved portion provided on an outer side of an upper end curved portion and having a curvature smaller than a radius of curvature of the upper end curved portion.
Further, the curl forming method of the mouth part of the can according to the present invention is a method of forming a curl part at the opening end of the mouth part of a can body having a bottom part, a body part, a shoulder part and a mouth part, A portion of the curl portion below the maximum outer diameter portion is bent and formed by crushing.

In the can body according to the present invention having such characteristics, the cross-sectional shape of the curled portion has a shape having resistance to a drop impact. Thus, the curled portion can have a desired sealing performance with respect to the cap attached to the mouth, and deformation of the curled portion due to a drop impact can be suppressed.
In addition, according to the curl forming method of the present invention, the portion below the maximum outer diameter part of the can curl part has a shape that has resistance to drop impact, or a desired sealing performance with respect to a cap that is attached to the mouth part. Can be formed into a shape that can be obtained.

It is explanatory drawing which showed the structural example of the can body (whole structure figure). It is the longitudinal cross-sectional view which showed the curl part of the can which concerns on embodiment of this invention. It is the longitudinal cross-sectional view which showed the sealing part of the curl part and cap of the can which concerns on embodiment of this invention. It is explanatory drawing which showed the curl part formation method in the mouth part of the can which concerns on embodiment of this invention ((a) is the state before a process, (b) The shaping | molding of spinning shaping | molding, (c) is spinning shaping | molding. After molding, (d) shows the molding process of crushing.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, the same reference numerals in different drawings indicate parts having the same function, and repeated description in each drawing will be omitted as appropriate.

FIG. 1 shows a configuration example of the can 1. The can 1 is, for example, a metal container having a bottom 1A, a trunk 1B, a shoulder 1C, and a mouth 1D. An example of the can 1 is a bottle can. The method for forming the bottle can is as follows. For example, a metal plate made of an aluminum alloy or the like is punched into a circular shape, and then drawn to obtain a bottomed cylindrical cup member, which is then redrawn and ironed to form a cylindrical can with a predetermined thickness. Get once. Thereafter, the neck 1 is reduced in diameter by a predetermined length from the open end of the cylindrical can to form the shoulder 1C and the mouth. Then, a bead portion and a screw portion are formed in the mouth portion by spinning, and then a side wall (side wall 2 described later) inclined upward inward is formed above the screw portion by neck-in processing. A bottle-shaped can body 1 having a mouth portion 1D is obtained by forming a curled portion 10 described below at the upper opening end by spinning.

The curled portion 10 is a portion that is processed into a curl shape by curving the opening end of the mouth portion 1D outward. The curled portion 10 is formed in an annular shape with substantially the same cross section around the mouth portion 1D.

The curled portion 10 provided in the mouth portion 1D of the can body 1 according to the embodiment of the present invention has a cross-sectional shape as shown in FIG. 2 (in the drawing, P1 is an imaginary line parallel to the can axis) ). That is, the curled portion 10 has an upper end curved portion 11 including the upper end of the mouth portion 1D, and a lower end 12A approaching or contacting the side wall 2 of the mouth portion 1D, and the upper side is inclined outward with respect to the can axis (virtual line P1). The cross-sectional shape of the outer wall curved portion 12 is a substantially inverted triangular shape having the side wall 2, the upper end curved portion 11, and the outer wall curved portion 12 of the mouth 1 </ b> D as three sides.

Such a cross-sectional shape of the curled portion 10 is structurally resistant to drop impact. Specifically, an inner connecting curved portion 13 is provided on the inner side of the upper end curved portion 11, and an outer connecting curved portion 14 is provided on the outer side of the upper end curved portion 11. The curvature radius R2 and the curvature radius R3 of the outer connecting curved portion 14 are both formed smaller than the curvature radius R1 of the upper end curved portion 11 to form a substantially inverted triangular corner.

More specifically, in the curled portion 10, the side wall 2 of the mouth portion 1D above the lower end 12A of the outer wall curved portion 12 is inclined upward inward with respect to the can axis (virtual line P1). By inclining the side wall 2 of the mouth portion 1D in this way, it is possible to receive an uneven load in the direction F shown in the figure by this inclination. Therefore, the curled portion 10 having such a cross-sectional shape has high resistance to the uneven load. have.

More specifically, the curled portion 10 is preferably formed so that the curvature radii of the upper end curved portion 11 and the outer wall curved portion 12 are substantially equal. According to this, the substantially inverted triangular shape due to the cross-sectional shape of the curled portion 10 becomes a substantially regular triangle, and has equal resistance to impact loads received from various directions. At this time, the outer connecting curved portion 14 becomes the maximum outer diameter portion 14 </ b> A in the curled portion 10.

FIG. 3 shows an example of the sealing structure of the curled portion 10 when the cap 3 is attached to the mouth portion 1D of the can 1. The curled portion 10 having the above-described cross-sectional shape forms a seal point by the outer connecting curved portion 14 biting into the sealing material (liner material) 3A of the cap 3 when the cap 3 is attached to the mouth portion 1D. And good sealability can be obtained. At this time, by setting the radius of curvature R3 of the outer connecting curved portion 14 to be smaller than the radius of curvature R1 of the upper-end curved portion 11 and setting it within an appropriate range, a curl that provides desired biting while preventing damage to the sealing material 3A is obtained. The shape of the part 10 can be obtained.

In addition, when the can body 1 is in a positive pressure state, the cap 3 is always subjected to a force to move away from the upper end of the mouth portion 1D. However, according to the cross-sectional shape of the curled portion 10, it becomes a seal point. Since the outer wall curved portion 12 that extends downward from the outer connecting curved portion 14 is inclined inward, the lower portion of the outer connecting curved portion 14 that bites into the sealing material 3A lifts the cap 3 by positive pressure. It has a locking action to stop, and an effective sealing effect can be obtained even when the can body is in a positive pressure state.

FIG. 4 shows an example of a method for forming the curled portion 10. (A) has shown opening end 1D1 before a process. Spinning molding as shown in (b) and (c) is performed on the opening end 1D1 as the first stage processing. Specifically, as shown in (b), a curved flange molding (spinning molding) is performed on the opening end 1D1 by pressing the first spinning die 20 from above. At this time, the curved shape (curvature radius R <b> 1) of the upper end curved portion 11 in the curled portion 10 is formed by the curved mold 20 </ b> A of the first spinning die 20. Next, as shown in (c), the inner connecting curved portion 13 formed inside the upper end curved portion 11 is formed by pressing the second spinning die 21. At this time, the bending shape (curvature radius R2) of the inner connecting bending portion 13 is formed by the bending die 21A of the second spinning die 21.

After that, as shown in (d), the remodeling tool 22 is pressed from the side and crushed as the second stage. By this crushing process, the outer wall curved portion 12 which is a portion below the maximum outer diameter portion of the curled portion 10 is curved. At this time, the remodeling tool 22 has a mold surface 22A that is curved so that the upper side is inclined outward with respect to the rotation center axis. Therefore, a part of the outer wall curved portion 12 formed thereby is crushed. Thus, the revolving tool 22 has a curved molding surface whose lower side is inclined inward with respect to the rotation center axis and the can axis (virtual line P1).

As described above, it is already known that the curled portion 10 is formed by a combination of spinning forming and crushing processing as shown in the related art. However, in the forming method of the present invention, a remodeling tool used in crushing processing is used. One feature is that the 22 mold surfaces 22A are curved surfaces whose upper side is inclined outward with respect to the rotation center axis. By using such a reforming tool 22, the cross-sectional shape of the curled portion 10 can be made into an effective substantially inverted triangular shape having resistance against a drop impact.

As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention. In addition, the above-described embodiments can be combined by utilizing each other's technology as long as there is no particular contradiction or problem in the purpose and configuration.

1: can body, 1A: bottom, 1B: trunk, 1C: shoulder, 1D: mouth,
2: side wall, 3: cap, 3A: sealing material,
10: curled portion, 11: upper end curved portion, 12: outer wall curved portion, 12A: lower end,
13: Inner connecting curved part, 14: Outer connecting curved part

Claims

A can body having a mouth portion and provided with a curled portion at an opening end of the mouth portion,
The curled portion is
An upper-end curved portion including an upper end of the mouth portion;
An outer wall curved portion whose lower end is close to or in contact with the side wall of the mouth portion and whose upper side is inclined outward with respect to the can axis;
An inner connecting curved portion provided inside the upper curved portion and having a radius of curvature smaller than that of the upper curved portion;
A can body comprising an outer connecting curved portion provided on an outer side of the upper-end curved portion and having a curvature smaller than a radius of curvature of the upper-end curved portion.
The can body according to claim 1, wherein a cross-sectional shape of the curled portion is a substantially inverted triangular shape having three sides of a side wall of the mouth portion, the upper end curved portion, and the outer wall curved portion.
The can body according to claim 1 or 2, wherein the side wall of the mouth portion above the lower end of the outer wall curved portion is inclined inwardly with respect to the can axis.
The can body according to any one of claims 1 to 3, wherein radii of curvature of the upper end curved portion and the outer wall curved portion are substantially equal.
The can according to any one of claims 1 to 4, wherein the outer connecting curved portion is a maximum outer diameter portion of the curled portion.
A can body having a bottom part, a body part, a shoulder part, and a mouth part, a method of forming a curled part at the opening end of the mouth part,
A curl portion forming method for a can body mouth portion, wherein a portion below the maximum outer diameter portion of the curl portion is crushed by crushing.
7. The method for forming a curl portion of a can body mouth portion according to claim 6, wherein the forming surface formed by the crushing process is formed so that the lower side is inclined inward with respect to the can axis.
The can body mouth according to claim 6 or 7, wherein a curved flange is formed by a spinning die at an opening end of the mouth portion as a first stage processing, and the crushing processing is performed as a second stage thereafter. Part curl forming method.