JP2002302194A - Capping method for threaded metal di can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent failure in forming a cap forgery-preventing skirt portion, which causes unsealing failure, in relation to a capping method for mounting a cap to a threaded metal can having a mouth around which an external thread is formed. SOLUTION: In a capper which uses an arbitrary number of rollers among a plurality of rollers as a threading roller and uses remaining rollers as a skirting roller, two rollers 56 are used as a skirting roller, and the capping processing is performed by mutually deviating positions of the two rollers 56 in a vertical direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a capping method for attaching a cap to a metal can with a screw, and more particularly, to a method for mounting a cap over a mouth of a metal can with a male screw around the mouth. The present invention relates to a capping method for mounting with a capper.

[0002]

2. Description of the Related Art In recent years, beer, low-malt beer, carbonated beverages, soft drinks, and other beverages have been packed in a metal can with a male screw around the mouth, and then sealed with a cap. Have become more popular. One type of metal cans used for such beverages in metal cans is polyethylene phthalate (PE).
T) Using a metal laminated with a resin material, for example, an aluminum strip, forming a tubular body such that the portion to be the mouth portion at the time of deep pressing of the can is the bottom, and then cutting the tip of the portion. An external thread is formed on the outer periphery of the mouth, and a separately formed bottom plate is attached to the bottom of the can by caulking to the cylindrical body. Laminated metal cans). Another type is a threaded metal DI can that is formed using a conventional metal DI can manufacturing process that is formed by squeezing a non-laminated metal, for example, an aluminum strip.

On the other hand, as shown in FIG. 1, a cap 1 for sealing a metal can with a screw is provided with a main body 2.
And a plurality of bridges 5 circumferentially separated by slits 4 and a skirt 6 on the opening end connected to the main body through a plurality of bridges 5. In some cases, the skirt portion is wrapped around the skirt portion of the metal can in a skirt winding step to be kept tightly closed, and the bridge 5 is cut by applying a torque to the main body portion of the cap when the cap is opened. When such a cap is attached to the mouth of a threaded metal can, a capping device, that is, a capper (hereinafter, capper) is used. In the conventional capping method using the capper, two or three out of four rollers of the capper are used.
Using the piece as a threading roller, thread the outer periphery of the main body of the cap along the male thread at the mouth of the metal can (here, threading does not actually cut, but male thread). Deforming the main body into a screw thread shape), using the remaining two or one roller as a hem winding roller, deforming the hem of the cap along the skirt of the metal can, It is fixed to the mouth.

[0004] Incidentally, the above-mentioned metal can with a screw, both a laminated metal can and a metal DI can, are usually formed by deep-pressing a material consisting of an aluminum strip.
The thickness of the can is thin. For this reason, liquid nitrogen is added after filling the beverage, not only when filling a beverage mixed with gas such as beer, low-malt beer, carbonated beverage, etc., but also when filling a beverage not mixed with gas. The internal pressure is set to a positive pressure higher than the atmospheric pressure to prevent crushing of the can. Moreover, in the case of a wide-mouthed metal can, the force acting on the cap outward from the inside of the can is larger than that of a narrow-mouthed metal can. For this reason, there is a problem that one or a plurality of bridges are naturally cut after the can is sealed with the cap, that is, a so-called bridge break occurs. When a bridge breaks, it cannot serve as evidence of bridge opening.

[0005] As a method of solving such a problem of the breakage of the bridge, a method of increasing the strength of the bridge, for example,
It is conceivable to increase the width of each bridge or increase the number of bridges. However, any method for increasing the strength of the bridge increases the necessary rotating force, ie, opening torque, applied to the cap when opening the cap. .
Then, the cap hem portion, which originally holds the connection between the threaded metal can and the cap main body and should be separated at the time of opening, rotates in synchronization with the cap main body, which causes a problem of poor opening.

[0006]

The inventors of the present invention have conducted intensive studies on the mechanism of poor opening of a metal can with a screw.
The present inventor has discovered that the problem is caused by poor formation of the cap hem, and obtained an idea that it is possible to eliminate the poor opening by improving the capping method, thereby completing the present invention.

An object of the present invention is to provide a method for capping a metal can with a screw which can prevent poor opening. Another object of the present invention is to provide a method for capping a metal can with a screw, which can prevent the cap from breaking a bridge by preventing molding defects of a screw and a hem of the cap.

[0008]

According to one aspect of the present invention, a capper is used in which an arbitrary number of rollers among a plurality of rollers are threaded rollers, and the remaining rollers are hem-wound rollers. In the capping method of attaching a cap to a screwed metal can having a mouth formed with a screw, a feature is that two rollers are used as hem-wound rollers, and the capping process is performed by displacing the rollers vertically with respect to each other. Have. In the above capping method, the capper uses four rollers, two of the rollers opposed to each other are threaded rollers, and the remaining two rollers are hem-wound rollers. The hem winding rollers are vertically displaced from each other, and the cap covered on the mouth portion is capped twice by one capper having two hem winding rollers shifted in the position. Is also good. Thus, in the present invention, it is possible to prevent poor molding of the cap hem and prevent poor opening of the cap.
In the above capping method, the capper may be 4
, And the capper is a first and a second two cappers, the three rollers of the first capper are threaded rollers, and the remaining one roller is a hem-wound roller. Performing capping processing of the cap put on the second capper.
The capping process of the cap capped by the first capper may be performed by using the two rollers as threading rollers and the remaining two rollers as hem-wound rollers. As a result, the thread of the cap can be firmly cut, bridge breakage of the cap can be prevented, molding failure of the cap hem can be prevented, and opening failure of the cap can be prevented. In the above capping method, the positional deviation of the skirt winding roller may be designed in consideration of the manufacturing tolerance of the skirt of the cap, and when the amount is δ, for example, 0 <δ ≦ 1 mm. Further, the radius of curvature of the outer peripheral edge of each roller may be designed in consideration of the thread root of the cap screw,
When the amount is R, for example, 0.7 mm ≦ R ≦ 1.1 mm may be satisfied. Furthermore, the relationship between the curl outer diameter of the mouth of the metal can and the inner diameter of the cylinder of the pressure block of the capper is determined in consideration of the manufacturing tolerance of the outer diameter of the cap and the inner diameter tolerance of the cylinder of the pressure block. It suffices if they are designed, and when they are D and d, for example, D + 1 mm ≦ d ≦ D + 3 mm.

According to another invention of the present application, an external thread is formed on the outer periphery by using a capper that uses an arbitrary number of rollers among the four rollers as thread cutting rollers and uses the remaining rollers as hem-wound rollers. Threaded metal DI with mouth
In the capping method of attaching a cap to a can,
The cap covered by the mouth part as a first and a second two cappers, three rollers of the first capper as threaded rollers, and the remaining one roller as a hem-wound roller The capping of the cap capped by the first capper is performed by using the two rollers of the second capper as threaded rollers and the remaining two rollers as hem-wound rollers. , In particular. As a result, even in the present invention, the cap can be threaded firmly, the bridge of the cap can be prevented from being cut, the molding failure of the hem portion can be prevented, and the opening failure of the cap can be prevented. In the above capping method, the radius of curvature of the outer peripheral edge of the threading roller may be designed in consideration of the manufacturing tolerance of the cap skirt, and when the amount is R, for example, 0.7 mm ≦ R ≦ 1. It may be 1 mm 2. Further, the relationship between the curl outer diameter of the mouth portion of the metal can and the inner diameter of the cylindrical portion of the pressure block of the capper is designed in consideration of the manufacturing tolerance of the outer diameter of the cap and the inner diameter tolerance of the cylindrical portion of the pressure block. When D and d are set, for example, D + 1 mm ≦ d ≦ D + 3 mm.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Prior to the description of a method for capping a metal can with a screw according to the present invention, first, an example of a metal DI can with a screw used to carry out the capping method of the present invention will be described. In FIG.
An example threaded metal DI can 10 is shown in cross section in the right half. The threaded metal DI can 10 includes a bottom 11, a tubular portion 12 formed integrally with the bottom, and a mouth 13 formed at an end of the tubular portion (an end opposite to the bottom). have. The mouth portion 13 has a smaller diameter than the cylindrical portion 12 and has an external thread 14 formed on the outer periphery thereof.
The process for manufacturing such a threaded metal DI can is briefly described as follows.

First, as shown in FIG. 3A, a can material, which is a thin strip material (non-laminate material) of aluminum, is deeply formed into a cylindrical portion 12 with a bottom portion 11 as shown in FIG. The open end is trimmed at a desired distance from the bottom as shown in FIG. 3B. Thereafter, when a decoration such as a pattern is provided on the outer periphery of the metal can, which is the final product, after performing processes such as washing and undercoating, such a pattern is printed on the outer periphery of the cylindrical portion 12 (up to this point). Is the same as the method for manufacturing a normal metal DI can), and a coating material is applied to the outermost surface for protection of the printed surface and dried. Next, after the inner surface processing step of the tubular portion 12 is completed, necking is performed on the opening of the tubular portion 12 to form the mouth portion 13 as shown in FIG. 3C. Further, the mouth 13
As shown in FIG. 3D, the skirt 1
After forming 5, the male screw 14 is formed in a screw forming step as shown in FIG. 3E. Finally, the opening edge 1 of the mouth
6, that is, the top surface is curled and formed into a final shape as shown in FIG. 3F, and the final product 10 is obtained through a secondary washing and drying process.

The threads of the male screw 14 formed on the outer periphery of the mouth portion 13 as described above are formed at a thread pitch of eight threads per inch, and as shown in FIG. Are not two peaks, and part A is one peak. In this embodiment, the number of bridges is eight, and the number of effective screws in the circumferential direction where the majority of the bridges exist is two, which is 1.7 turns when expressed as the number of effective screw turns of the screw thread. . Thus, the fact that the effective number of turns is 1.7 means that the number of threads is two in the area of 70% of the outer periphery of the mouth, and the remaining 30%.
Indicates that the number of threads is one only in the region of. Further, when the metal can as a product is sealed with the cap, the sliding between the metal can and the cap is improved when the cap is opened, and the opening torque (rotational force applied to the cap required to open the cap) is not increased. For this purpose, in the above-mentioned coating material application step, a resin obtained by adding a polyethylene wax to a polymerized polyester / amino resin was applied as a coating material.

Next, an embodiment of the capping method of the present invention for attaching a cap to the mouth of the above metal DI can with a screw will be described. In this method, capping is performed using a conventional capper having two thread cutting rollers and two hem winding rollers, while partially changing the position of the hem winding roller. As shown in FIGS. 5 and 6, the capper 50 is supported by a capper body (not shown) so as to be able to move up and down, and presses the cap 1 covered on the opening 13 of the threaded metal DI can 10 from above. A pressure block 51, and two threading rollers 55 supported by the capper body via a support shaft 57 and arranged in diametrical directions of a circle centered on the center axis YY of the pressure block; Also, the screwing roller 55 is supported by the capper body via a support shaft 58 and is opposed to the diameter direction of a circle centered on the center axis Y-Y of the pressure block and is shifted by 90 ° in the circumferential direction of the threading roller 55. And two hem windings 56 formed. In the pressure block 51, the top plate 3 of the cap 1 is
Inner part 52 which is pressed from above towards the edge of the mouth of the I-can
And a cylindrical portion 53 arranged on the outer peripheral portion of the inner portion. The threading roller 55 and the hem winding roller 56
It turns simultaneously about the axis YY and is rotatable about its own rotation axis yy. In addition, the threading roller 55 and the hem winding roller 56 swing by the support shafts 57 and 58 moving radially inward and outward about the axis Y-Y, or by swinging the support shafts 57 and 58 about the upper end. By doing so, it is possible to move radially inward and outward about the axis Y-Y. Further, each of the threading rollers 55 is independently movable in the vertical direction relative to the pressure block 51, and the two hem winding rollers 56 are simultaneously moved in the vertical direction. . The set positions of the two hem winding rollers are slightly shifted in the vertical direction as shown in FIG. This shift amount δ may be 0 <δ ≦ 1 mm. Each of the rollers 55 and 56 has a center portion 551, 561 that is thicker and linearly thinner toward the outer peripheral edges 552, 562.
It has the shape of an abacus ball, and the outer peripheral edges 552 and 562 are rounded with a radius of curvature. Here, as shown in FIG. 8, the radius of curvature R of the threading roller 55 is 0.7 mm ≦
It is preferable that R ≦ 1.1 mm. The inner diameter d of the cylindrical portion 53 of the pressure block 51 is a metal DI.
When the outside diameter of the curl of the mouth of the can 1 is D, (D +
1) It is preferable that mm ≦ d ≦ (D + 3) mm.

When the capping process is performed with the above-mentioned capper, the capping process is performed twice with the same capper as follows. In the first capping process, first, FIG.
As shown in [A] and [B], cover the mouth portion 13 with the cap 1 and press the pressure block 51 of the capper 50.
Is lowered from above the cap, and the top plate 3 of the cap is pressed toward the mouth of the metal DI can by the inner portion 52, and the sealing member disposed in the cap is moved to the opening edge 1 of the mouth.
6 is pressed. When the pressure block descends, the lower end edge of the outer cylindrical portion 53 projects below the inner portion 52, so that the periphery of the top plate 3 of the cap 1 is closed by a mouth of a threaded metal DI can. According to the shape of the part 13,
It is deformed downward (FIG. 8C). After that, FIG.
As shown in FIG. 5, two threading rollers 55 and two hem winding rollers 56 of the capper 50 are simultaneously rotated along the axis Y-.
Y is turned around and the threading roller 55
And the skirt winding roller 56 is gradually moved toward the axis Y-Y. Then, the outer periphery of the main body 2 of the cap is threaded along the outer periphery of the main body 2 of the cap 1 along the shape of the external thread formed in the mouth portion 14 (here, threading is
Instead of actually performing the cutting process, the cap body is pressed with a threading roller to deform it into a thread root along the external thread of the metal can.) The portion 16 is deformed along the skirt portion of the metal DI can and a hem winding process is performed. The reason that the cap can be threaded in this way is that the threading roller not only pivots about the axis Y-Y and moves towards that axis, but also can move down along the external thread of the metal DI can. That's why. In the first capping process, approximately 60% to 70% of the entire process is performed. Then, after performing the first capping process, the cap is kept pressed by the pressure block 51, and then the second capping process is performed in the same manner as described above.
The capping process of the cap is completed.

Next, another embodiment of the capping method of the present invention will be described. In this method, a capping process is performed using first and second two cappers.
The first capper used in this method is shown in FIGS.
Are different from those shown in FIG. 1 only in the number of threading rollers and hem-wrapping rollers. Therefore, only the differences will be described, and other descriptions will be omitted. As shown in FIG. 9, the first capper 50a is provided with three threading rollers 55a which are arranged (displaced by 90 °) in a circumferential direction of a circle centered on the center axis YY. , One hem winding 56a arranged at a position where the threading roller is not arranged on the circumference around the center axis Y-Y. Other structures are the same as the capper of the above embodiment. The second capper is the same as the capper shown in FIGS. 5 and 6, and a description thereof will be omitted.

When the capping process is performed by the two cappers, the following process is performed. In the first capping process by the first capper, first, as shown in FIGS. 10A and 10B, the cap 13 is put on the mouth portion 13 and the
The pressure block 51a is lowered from above the cap, and the top plate 3 of the cap is pressed toward the mouth of the metal DI can by the inner portion 52a, and the sealing member arranged in the cap is opened at the opening end of the mouth. The edge 16 is pressed. When the pressure block descends, the lower end edge of the outer cylindrical portion 53a projects below the inner portion 52a. It is deformed downward along the shape of the part 14 (FIG. 10C). Thereafter, as shown in FIG. 10D, the three threading rollers 55 of the capper 50a are
a and one skirt winding roller 56a are simultaneously turned around the axis Y-Y, and the threading roller 55a and the skirt winding roller 56a are gradually moved toward the axis Y-Y. Then, the outer periphery of the main body 2 of the cap is threaded along the outer periphery of the main body 2 of the cap 1 along the shape of the external thread formed in the mouth portion 13 (here, the threading means
Rather than actually performing the cutting process, the cap body is pressed by a threading roller to deform it into a thread valley along the external thread of the metal can.) The portion 16 is deformed along the skirt portion of the metal DI can and a hem winding process is performed. In this first capping process, about 60% to 70% of the whole
Is performed. After performing the first capping process, the metal DI can is moved to the position of the second capper, and the second capping process is performed by the second capper. The second capping is the same as the first capping, except that the thread is cut by two threading rollers and the hem winding process is performed by the two hem winding rollers, and therefore the description is omitted. Completion of the second capping process completes the cap capping process of this embodiment.

[0017]

According to the present invention, the following effects can be obtained. (A) Since the hem winding of the hem of the cap can be reliably performed, poor molding of the hem can be prevented, and poor opening of the cap can be prevented. (B) Since the screw of the cap can be precisely formed in accordance with the external thread of the metal DI can with a screw, it is possible to suppress the occurrence of bridge breakage of the cap after sealing with the cap.

[Brief description of the drawings]

FIG. 1 is a side view of a cap used to seal a threaded metal DI can.

FIG. 2 is a side view showing a cross section of one side of a metal DI can with a screw to which the capping method of the present invention is applied.

FIG. 3 is a view for explaining a manufacturing process of the metal DI can with a screw of FIG. 2;

FIG. 4 is an enlarged side view of the mouth of the metal DI can with thread of FIG. 2;

FIG. 5 is a schematic perspective view of a capper that performs an embodiment of the capping method of the present invention.

6 is a side sectional view of the capper of FIG. 5, showing a basic configuration of the capper.

FIG. 7 is an enlarged sectional view of a peripheral portion of a thread cutting roller and a hem winding roller.

FIG. 8 is an explanatory diagram of a capping step performed using the cappers of FIGS. 5 and 6.

FIG. 9 is a schematic perspective view of a capper that performs another embodiment of the capping method of the present invention.

FIG. 10 is an explanatory diagram of a capping step performed using the capper of FIG. 9;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Cap 2 Main body part 3 Top plate 4 Slit 5 Bridge 6 Hem part 10 Metal DI can with a screw 11 Bottom 12 Cylindrical part 13 Mouth part 14 Screw 50, 50a Capper 51, 51a
Pressure block 55, 55a Threading roller 56, 56a
Hem winding roller

Continued on the front page F term (reference) 3E080 AA08 CE05 CF02

Claims (9)

[Claims] 1. A threaded screw having an external thread formed on an outer periphery thereof by using a capper using an arbitrary number of rollers among a plurality of rollers as thread cutting rollers and using the remaining rollers as hem winding rollers. A capping method for attaching a cap to a metal can, comprising using two rollers as hem-wound rollers and performing capping processing by displacing the rollers vertically with respect to each other. 2. The method according to claim 1, wherein the capper uses four rollers, two of the rollers facing each other are threaded rollers, and the remaining two rollers are threaded rollers. Using two rollers as skirt winding rollers, and performing capping processing on the cap covered on the mouth twice by one capper having two skirt winding rollers shifted in the position. To cap metal cans with screws. 3. The method according to claim 1, wherein the capper uses four rollers, the capper being a first and a second two cappers, wherein the first capper is used. The capping process of the cap covered on the mouth is performed by using the three rollers as threaded rollers and the remaining one roller as a hem-wound roller, and the two rollers of the second capper are threaded rollers. And capping the cap that has been capped by the first capper using the remaining two rollers as hem-wound rollers. 4. The method for capping a metal can with a screw according to claim 1, wherein the displacement δ of the hem winding roller is 0 <δ ≦ 1 mm. Capping method for metal cans. 5. The method for capping a threaded metal can according to claim 1, wherein a radius of curvature R of an outer peripheral edge of the threading roller is set to 0.7 mm ≦ R ≦ 1.1 mm. A method for capping a metal can with a screw. 6. The capping method for a metal can with a screw according to claim 1, wherein the outer diameter of the curl of the mouth of the metal can is D, and the inner diameter of the cylinder of the pressure block of the capper is D. A method for capping a metal can with a screw, wherein d + 1 mm ≦ d ≦ D + 3 mm. 7. A screw having an external thread formed on its outer periphery by using a capper using an arbitrary number of rollers among the four rollers as thread cutting rollers and using the remaining rollers as hem winding rollers. In a capping method of attaching a cap to a metal can with a cap, the capper is a first and a second two cappers, three rollers of the first capper are threaded rollers, and the remaining one roller is hem-wrapped The capping process of the cap covered on the mouth portion as a roller is performed. The two rollers of the second capper are threaded rollers, and the remaining two rollers are hem-wound rollers. A method for capping a metal can with a screw, comprising performing capping of the cap after capping. 8. The method according to claim 7, wherein a radius of curvature R of an outer peripheral edge of the threaded roller is 0.7 mm ≦ R ≦ 1.1 mm. Metal can capping method. 9. The method for capping a metal can with a screw according to claim 7 or 8, wherein the curled outer diameter of the mouth of the metal can is D, and the inner diameter of the cylinder of the pressure block of the capper is d. Wherein (D + 1) mm ≦ d ≦ (D + 3) mm.