JP2002234536A - Tab and manufacturing method therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase rigidity of a tab and to provide a can lid which does not give a sense of incongruity when a canned beverage or the like is taken by preventing a tear-out protrusion or the like from projecting from an outer periphery of a push-down portion. SOLUTION: In the tab which is formed by cutting from a strip metal piece, the push-down portion 7 has the tear-out protrusion 3a' left on a side of the tab 10 after it is cut off from a stitch carry 3a for coupling and holding the tab 10 with the strip metal piece while the tab 10 is machined, and is equipped with fold-backs 7a which are adjacent to both sides of the protrusion 3a' and have a curled cross section comprising at least a triple structure of metallic plates. The protrusion 3a' is formed in approximately the same outer peripheral form not to project from the outer periphery of the push-down portion 7, and a gap between the fold-backs 7a located to face a panel is made small to a degree that the protrusion 3a' can be received.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an easily opened can lid which can be easily opened by a tab, and more particularly to a can lid having safety during drinking and strength of the tab.

[0002]

2. Description of the Related Art Conventionally, as a can lid that can be opened by a tab, a stay-ion tab (SOT) type can lid is known. This is a can lid configured to contribute to environmental preservation and resource recovery, etc. by leaving a tab for opening the lid and an opening piece cut out by the tab in a state attached to the can lid even after the lid is opened. It is. Specifically, a tab integrally formed at the center of the flat upper surface portion (panel portion) of the can lid is attached to the can lid by rivets, and the panel portion is positioned at the tip of the tab, that is, below the depressed end. The opening is defined by an open score line with both ends separated from each other so that a connecting portion remains at the portion where the connection is made. Therefore, by lifting the rear end of the tab, that is, the lifting end, the tab and the rivet exert a leverage action to relatively push up the opening piece, thereby causing a break in the score line and placing the opening piece inside the can. The opening piece is connected to the panel portion by a connecting portion formed by pushing in and separating the ends of the score lines from each other.

On the other hand, the tab is stamped into a strip-shaped metal piece, formed into a predetermined shape, and then cut off from the strip-shaped metal piece. When such a tab is separated from the strip-shaped metal piece, if the tab is cut just at the outer peripheral portion, it is not preferable because the outer peripheral portion of the tab may be cut by a cutting tool. Therefore, cutting is generally performed outside the outer peripheral portion. However, in this case, the separation convex portion, which is a cut end of the separation portion formed when the tab and the strip-shaped metal piece are separated, protrudes from the outer peripheral portion of the tab, giving a sense of incongruity.

A can lid in which the cut end of the cut-off portion is not projected is described in JP-A-9-221132. In this publication, the tab 100 shown in FIG.
As shown in the bottom view of FIG. 5 and the cut end view of the can lid in FIG. 5 (b), the tab 100 is gradually inclined away from the panel 102 with respect to the vicinity of the rivet 101 to the tip.
a, and a panel abutting portion 100b that curls from the tip of the inclined portion 100a toward the panel 102 and further reaches the vicinity of the rivet 101 along the panel 102 at the tip. The panel contact portion 100b is
The tab 100 is formed by a pair of folded tongues 100c that curl from the tip of a toward the panel 102 and further extend along the panel 102 to the vicinity of the rivet 101.
Of the tongue 100c, and the separation projection 100d is provided between the bases of the both folded tongues 100c.
It is formed so that it curls inward from the tip of the. Therefore, the disconnecting convex portion 100d does not protrude into the drinking spout, and does not give an uncomfortable feeling when drinking after opening.

[0005]

However, in order for the detaching projection 100d to be wound inside, the detaching projection 1
It is necessary to increase the gap between the bases of the folded tongues 100c as a space for accommodating 00d. However, if the gap is increased, the rigidity of the tab in the vicinity of the folded tongue 100c is impaired. On the other hand, as shown in FIG. 5C, when the space for accommodating the separation protrusion 100d is reduced,
There is a problem in that the periphery of the separation convex portion 100d becomes excessive, and a protruding portion is generated, giving a sense of incongruity.

The present invention has been made in view of the above-mentioned problems, and increases the rigidity of a tab and prevents canned beverages and the like from being prevented from protruding from the outer periphery of a depressed portion, while allowing canned beverages to be drunk. It is an object of the present invention to provide a can lid that does not sometimes give a sense of discomfort.

[0007]

According to the first aspect of the present invention, a strip-shaped metal piece is cut out and formed, attached to a panel portion of a can lid with a rivet, and an outer peripheral edge is curled toward a side facing the panel portion. In the tab which is processed and lifts the lifting part, the pressing part cuts off the opening piece provided in the panel part of the can lid, in the pressing part,
While processing the tab, the tab is connected and held to the band-shaped metal piece, and has a separation convex portion that is cut off when separating the band-shaped metal piece and the tab and remains on the tab side, and the separation is performed. Adjacent to both sides of the convex portion, a folded portion whose curled cross section has at least a triple structure of a metal plate is provided, and the separated convex portion has substantially the same outer peripheral edge so as not to protrude from the outer peripheral edge of the press-down portion. The gap between the folded portions located on the side facing the panel portion is made small enough to accommodate the separation convex portion.

According to the second aspect of the present invention, the strip-shaped metal piece is cut out and formed, attached to the panel portion of the can lid with a rivet, the outer peripheral edge is curled toward the side facing the panel portion, and the lifting portion is formed. In the method of manufacturing a tab in which the pushing-down portion cuts an opening piece provided in the panel portion of the can lid by lifting, the tab is connected to and held by the strip-shaped metal piece while the tab is being processed in the pushing-down portion. Forming a cut-off portion to be cut thereafter, adjacent to both sides of the cut-off portion on the side facing the panel portion,
A folded portion having a curled cross-section having at least a metal plate triple structure is formed, and a cut-off convex portion remaining on the tab side is formed by cutting the cut-off portion. The cut-off convex portion is separated from the strip-shaped metal piece. A tab having rivets is attached to the can lid by rivets, and after attaching the tab to the can lid, a wipe-down molding process is performed in which the separation convex portion is placed in a gap between the folded portions so as to have substantially the same outer peripheral edge shape of the tab. It is characterized by performing.

According to a third aspect of the present invention, in the method for manufacturing a tab according to the second aspect, a relief hole is provided which forms a part of the separation portion and an outer peripheral edge of the tab and has a plurality of curved portions. The shape of the hole is a shape that minimizes the gap between the folded portions adjacent to both sides of the separating portion, and the punch for punching the relief hole is a punch having a flat convex surface at the tip, and the convex surface The outer peripheral shape of the convex plane and the plurality of curved portions located on the tab side as close as possible, and after forming the relief hole, deburring the cut end surface which is the outer periphery of the relief hole and is on the tab side. The blade width of the cutter at the time of performing the processing and cutting the cut-off portion is at least twice the width of the cut-off portion.

[0010]

According to the tab of the present invention, the tab is connected to and held by the strip-shaped metal piece during the processing of the tab, and the tab is cut from the strip-shaped metal piece at the press-down portion of the tab. A separation projection is provided on the tab side.
A folded portion is provided adjacent to both sides of the separation convex portion, and has a curled cross section having at least a metal plate triple structure. Then, while making the separation convex portion substantially the same outer peripheral edge so as not to protrude from the outer peripheral edge of the push-down portion, the gap between the folded portions located on the side facing the panel portion is reduced to such an extent that the separating convex portion is accommodated. ing.

[0011] Accordingly, while the strength of the depressed portion of the tab is ensured, the depressed portion has no protrusion due to a gap or excess wall, so that the can lid can be reliably opened and consumed even when drinking after opening the can lid. Does not cause discomfort to the person.

In the method of manufacturing a tab according to the second aspect, the tab is connected to and held by the strip-shaped metal piece while the tab is being machined in the depressed portion, and a separating portion which is cut thereafter is formed, and the panel portion is formed. On the side that faces and is adjacent to both sides of the separation part, the folded part whose curled cross section has at least a metal plate triple structure is molded, and the separation convex part remaining on the tab side is formed by cutting the separation part. After the tab is attached to the can lid, the separation convex portion is placed in the gap between the folded portions, thereby performing the wipe-down molding so that the tab has substantially the same outer peripheral edge shape.

[0013] That is, the processing of the tab projecting convex portion is as follows.
In consideration of the production speed of the tab, it is necessary to work after the tab is cut off from the metal strip. Therefore, after the tab is separated, the tab is attached to the can lid with a rivet, and by performing the wipe-down molding, it is not necessary to renew the positioning of the tab without deteriorating the manufacturing speed of the tab, and the separation convex portion is provided. Can be reliably accommodated in the gap, so that the tabs have substantially the same outer peripheral edge shape.

According to a third aspect of the present invention, there is provided a method of manufacturing a tab, wherein a relief hole which forms a separation portion and a part of an outer peripheral edge of the tab and has a plurality of curved portions is provided. The gap between the folded portions adjacent on both sides is formed as small as possible. The punch for punching the relief hole is a punch having a flat convex surface at the tip, and the outer peripheral shape of the convex surface is as close as possible to the outer periphery of the convex surface and the plurality of curved portions located on the tab side. It is shaped.

Here, the features of the punch shape will be described with reference to the example shown in FIG. FIG. 3A shows a top view and a side view of the piercing punch 20 according to the prior art.
(B) shows a top view and a side view of the piercing punch 21 in the present embodiment. The piercing punches 20 and 21 are shown in FIG.
It moves in the direction of the arrow shown in the side view of (a) and (b) and punches out a strip-shaped metal piece. Piercing punch 2 in the prior art
At 0, the area indicated by oblique lines in the figure is a flat portion.
The piercing punch 20 had a convex shape with a flat tip, and the flat portion was formed in a direction perpendicular to the separating portion. By making the piercing punch 20 convex, it is possible to sequentially cut the periphery of the portion to be processed and reduce the load applied at one time. When punching out a relief hole which forms a part of the separation portion and the outer peripheral edge of the tab and has a plurality of curved portions, the flat portion first contacts the coil, and the portion a in FIG. Later, it is gradually cut along the arrow and finally b on the scrap side
And c on the tab side are cut off and completely punched out. In this case, since b is cut simultaneously in a straight line, burrs are unlikely to occur, but burrs occur at the corner c.
Therefore, c is the burr occurrence location.

Therefore, the piercing punch 21 in which the position of the flat portion is changed so that no burr is generated on the tab side c.
FIG. 3B shows a top view and a side view of FIG. By changing the position of the flat portion to a position where the outer periphery of the flat portion and the plurality of curved portions located on the tab side are as close as possible, first, FIG.
After the part d in (b) has been cut, it is gradually cut along the arrow, and finally the parts e, f and g are respectively cut. In this case, for the flat part, f and g
In the case of g, the distance g from the flat portion is farther, so that burr is generated in the direction g. Therefore, e and g are burrs where the burrs are generated, and the generation of burrs on the tab side can be suppressed.

Further, after the relief hole is formed, deburring is performed on the cut end surface on the outer periphery of the relief hole and on the tab side, and the blade width of the cutter when cutting the cut portion is at least two times the width of the cut portion. It is more than double. In other words, if the cutting part is cut by a cutter with a blade width almost the same as the width of the cutting part, a part of the cutting part will not be cut due to misalignment, etc. It's easy to do. However, by setting the blade width to be at least twice as large as that of the cut-off portion, even if a displacement or the like occurs, the entire cut-off portion can be reliably cut, and the occurrence of burrs can be suppressed.

That is, since there are no burrs or protrusions, there is no unpleasant sensation when drinking.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a tab process of forming a tab 10 from a strip-shaped metal piece according to the embodiment.

In step S1, a ring hole 1 serving as a finger hook portion on a metal strip, a tongue piercing 2 serving as a fulcrum together with a rivet at the time of opening, and a stitch carry (separating portion) serving as a connecting bar in a progressive feeding process and being cut later. Part)
A punching step of forming a pair of relief holes 3 forming one side of 3a and the folded portion 7a is performed.

Here, the shape of the relief hole 3 will be described. FIG. 2 is an enlarged view of the relief hole 3. In FIG. 2A, the hatched area is an area that is enlarged and reduced in comparison with the conventional relief hole shape in the present embodiment. As shown in FIG. 2B, a gap is formed in the folded portion 7a in the vicinity of the stitch carry 3a in the conventional relief hole shape, but by providing a reduced area in the relief hole shape, the stitch carry 3
The gap between the folded portions 7a in the vicinity of “a” is reduced. That is, by setting A <A ′, D> D ′ as shown in the figure, the gap between the folded portions 7a can be reduced, and the rigidity of the tab press-down portion 7 can be increased. Also,
By providing the enlarged area as B <B ', C>C' in the relief hole shape, the root portion of the separation convex portion 3a 'can be cut larger than before, and after separating the stitch carry 3a, the tab 10 side Even if the wipe-down molding for curling the separation convex portion 3a 'of FIG.
As shown in FIG. 5C, the tab-side separation projection 3a '(FIG. 5)
In (c), there is no excess in the root portion of 100d), and the separation convex portion 3a 'is formed in a shape that is easy to bend.

Next, a piercing punch for punching the relief hole 3 will be described. FIG. 3A shows a top view and a side view of the piercing punch 20 according to the prior art.
(B) shows a top view and a side view of the piercing punch 21 in the present embodiment. The piercing punches 20 and 21 are shown in FIG.
It moves in the direction of the arrow shown in the side view of (a) and (b) and punches out a strip-shaped metal piece. Piercing punch 2 in the prior art
At 0, the area indicated by oblique lines in the figure is a flat portion.
The piercing punch 20 had a convex shape with a flat tip, and the flat portion was formed in a direction perpendicular to the stitch carry 3a. By making the piercing punch 20 convex, it is possible to reduce the load applied at one time and punch the relief hole 3 as compared with the case where the entire surface is the same height. When the relief hole 3 is punched, the flat portion first contacts the strip-shaped metal piece, and after the portion a in FIG. 3A is cut, the flat portion is gradually cut along the arrow, and finally is cut. The b on the scrap side and the c on the tub side are cut and completely punched out. In this case, b is cut at the same time in a straight line, so that burr hardly occurs,
Burrs occur at the corner c. Therefore, c is the burr occurrence location.

FIG. 3B is a top view and a side view of the piercing punch 21 in which the position of the flat portion is changed so that no burr is generated on the tab c side. By changing the position of the flat portion to a position where the outer periphery of the flat portion and the plurality of curved portions located on the tab side are as close as possible, after the portion d in FIG. And e, f and g are finally cut. In this case, for the flat part, f
G is farther from the flat part than g
Burrs are generated toward g. Therefore, e and g are burrs where they occur, and burrs on the tab 10 side can be suppressed.

In step S2, an outer lance step is performed in which the outer shape of the tab is cut by the outer lance 4 so that the strip-shaped metal piece and the tab are connected only via the stitch carry 3a. In this step, the outer shape of the tab is cut out, and the peripheral edge of the relief hole 3 on the tab 10 side is rounded to crush the burrs generated in the step of removing the relief hole.

In step S3, a U-form process for bending the outer shape cut by the outer lance 4 substantially vertically along the shape of the tab is performed.

In step S4, the substantially vertically bent portion is curled, and further flattened to form a folded portion 7.
A flattening step for forming a is performed.

In step S5, the stitch carry 3a
Is cut off to separate the processed tab from the strip-shaped metal piece. At this time, the cutting is performed using the cut edge, but the blade width is set sufficiently larger than the width of the stitch carry 3a (at least twice the width of the stitch carry 3a). This prevents a part of the stitch carry 3a from being cut off due to a positional displacement of the tab in the width direction, thereby preventing a tip burr generated due to a broken state. Although the description of the processing of the rivet hole 5 and the panel forming processing of the part fixed by the rivet surrounded by the tongue piercing 2 is omitted, the processing is performed as needed.

The tab formed in the above process is fixed to the can lid 15 by rivets, and the detaching projection 3a 'of the stitch carry 3a protruding from the outer periphery of the press-down portion 7 of the tab by the wipe-down punch 11 shown in FIG. Is performed into the gap between the folded portions by wipe-down molding.
If this wipe-down molding is incorporated into the manufacturing process of the tab, the production speed of the tab is reduced, so that the productivity is reduced. Therefore, it is necessary to carry out after fixing to the can lid 15 by rivets. In this case, even if the tab is rotated around the rivet when the tab is fixed to the can lid, the key ring pilot 12 having the convex portion that fits into the ring hole 1 of the tab can be inserted into the ring hole 1. , The tab can be positioned at a predetermined position, and the separation projection 3a 'can be securely wiped down. By this wipe-down molding, the separation convex portion 3a 'of the stitch carry 3a can be made substantially the same arc shape so as not to protrude from the outer periphery of the press-down portion 7 of the tab, so that even when the consumer drinks a beverage or the like after opening, Does not give a sense of discomfort.

As described above, in the present embodiment, the folded portion 7a is provided adjacent to both sides of the separating convex portion 3a 'and has a curled cross-section having at least a metal plate triple structure. 3a 'depressed part 7
And a folded portion 7a located on the side facing the panel portion so as not to protrude from the outer peripheral edge of the panel.
The gap between them is cut off to such an extent that the projection 3a 'is separated. Therefore, while ensuring the strength of the press-down portion 7 of the tab 10, the press-down portion 7 has no protruding portion due to a gap or excess wall, so that the can lid 15 can be reliably opened and the can lid 15 can be opened.
The consumer does not feel uncomfortable when drinking after opening.

Further, in consideration of the production speed of the tab, the separation convex portion 3a 'of the tab 10 needs to be processed after being separated from the strip-shaped metal piece. Therefore, after the tab 10 is separated, by performing the wipe-down molding in a state where the tab 10 is attached to the can lid 15 by a rivet, it is not necessary to newly reposition the tab 10, and the separation convex portion 3 a ′ is surely formed. The tab 10 can be housed in the gap so as to have substantially the same outer peripheral edge shape.

Also, a stitch carry (separation part) 3
a and a part of the outer peripheral edge of the tab, and a relief hole 3 having a plurality of curved portions is provided.
Is a shape that minimizes the gap between the folded portions 7a adjacent to both sides of the stitch carry 3a. The piercing punch 21 for punching the relief hole 3 is a punch having a flat convex surface at a part of the tip, and the outer peripheral shape of the convex surface is a plurality of punches located on the outer periphery of the convex surface and the tab 10 side. The shape is such that the curved portion is as close as possible. Therefore, generation of burrs on the tab 10 side can be suppressed.

Further, after the relief hole 3 is formed, in the outer lance step, deburring is performed on the cut end face of the separation convex portion 3a 'on the outer periphery of the relief hole 3 and on the tab 10 side, and the stitch carry 3a is removed. The blade width of the cut edge at the time of cutting is at least twice as large as the width of the cut-off portion. In other words, when cutting the stitch carry 3a, if the cut is made with a cut edge having a blade width substantially equal to the width of the stitch carry 3a, a part of the cut portion is not cut due to a positional shift or the like, resulting in a torn state. Burrs are likely to occur. However, by setting the blade width to be at least twice as large as the stitch carry 3a, even if a misalignment or the like occurs, the entire stitch carry 3a is reliably cut, and the occurrence of burrs can be suppressed.

That is, since there are no burrs or protrusions, there is no sense of incongruity when drinking.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a manufacturing process of a tab in an embodiment.

FIG. 2 is a diagram illustrating a shape of a relief hole according to the embodiment and the related art.

FIG. 3 is a diagram illustrating a shape of a piercing punch according to the embodiment and the related art.

FIG. 4 is a diagram illustrating wipe-down molding in the embodiment.

FIG. 5 is a diagram showing a tab of the related art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Ring hole 2 Tongue earring 3 Relief hole 3a Stitch carry (separation part) 3a 'Separation convex part 4 Outer lance 5 Riveted hole 7 Depressed part 7a Folded part 10 Tab 11 Wipe down punch 12 Key ring pilot 15 Can lid 20 Pierce punch 21 Pierce Punch 100 Tab 100a Inclined part 100b Panel contact part 100c Folded tongue part 100d Separating convex part 101 Rivet 102 Panel

Claims (3)

[Claims] 1. A metal sheet is formed by cutting out from a strip-shaped metal piece.
A tab which is attached to a panel portion of the can lid by a rivet, an outer peripheral edge is curled toward a side facing the panel portion, and a lifting portion is lifted to push down a tab provided at the panel portion of the can lid to cut an opening piece. In the press-down portion, the tab is connected to and held by the strip-shaped metal piece while the tab is being processed, and the separation protrusion that is cut when the strip-shaped metal piece and the tab are separated and remains on the tab side. A folded portion adjacent to both sides of the separation convex portion and having a curled cross section having at least a metal plate triple structure, so that the separation convex portion does not protrude from the outer peripheral edge of the depressed portion. A tab having the same outer peripheral edge and having a gap between the folded portions located on the side facing the panel portion small enough to accommodate the separation convex portion. 2. It is formed by cutting out from a strip-shaped metal piece,
A tab which is attached to a panel portion of the can lid by a rivet, an outer peripheral edge is curled toward a side facing the panel portion, and a lifting portion is lifted to push down a tab provided at the panel portion of the can lid to cut an opening piece. In the manufacturing method, the tab is connected to and held by the strip-shaped metal piece while the tab is being processed, and then a cut-off portion to be cut is formed, and the side facing the panel portion is formed. Forming a folded portion adjacent to both sides of the separating portion and having a curled cross section having at least a metal plate triple structure, and forming a separating convex portion remaining on the tab side by cutting the separating portion; A tab separated from the metal piece and having a separation convex portion is attached to the can lid with a rivet. After attaching the tab to the can lid, the separating convex portion is folded back. Tab method for manufacturing which is characterized in that by paying the gaps between parts performing substantially wipe down molded to the same outer peripheral edge shape of the tub. 3. The method for manufacturing a tab according to claim 2, wherein a relief hole that forms a part of the separation portion and the outer peripheral edge of the tab and has a plurality of curved portions is provided, and the shape of the relief hole is determined by the separation. The shape of the gap between the folded portions adjacent to both sides of the portion is made as small as possible, the punch for punching the relief hole is a punch having a flat convex surface at the tip, and the outer peripheral shape of the convex surface is The outer periphery of the plane and the plurality of curved portions located on the tab side are formed as close to each other as possible. After the formation of the relief hole, a deburring process is performed on the cut end surface that is the outer periphery of the relief hole and is on the tab side. A method for producing a tab, characterized in that the blade width of the cutter when cutting the tab is at least twice the width of the cut-off portion.