JP2019011088A - Manufacturing method of can - Google Patents

Abstract

To provide a manufacturing method of a can capable of manufacturing the can in which a tail part is tipped up without hindering transport of a can lid.SOLUTION: A manufacturing method of a can having a tightening step of tightening, to an opening of a can body, a can lid including a can lid body and a tab 1 for the can lid fixed to a top face of the can lid body. The tab for the can lid includes: a fixing part formed by projecting to the top face of the can lid body and fixed to a rivet; a tip part overlapped on an opening piece defined by a score on the can lid body; and a tail part 8 extending in a direction opposite to the tip part with respect to the fixing part. The manufacturing method includes a tab bending step of, after the tightening step, floating an end part of the tale part upward from a disk shaped panel part disposed at a central part of the can lid body.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a can manufacturing method for manufacturing a can by winding a can lid having a tab around an opening of a can body.

As a can lid of a beverage can, a steion tab type that can open a drinking mouth with the tab attached to the can lid body is known. This steion tab type can lid has been proposed in which the lid can be opened easily even with a weak force when the tab is raised.
For example, in Patent Document 1, a V-shaped groove is provided in the entire center of the upper surface of the tab, a finger is hooked on the tip of the finger insertion, the tip is lightly lifted, and the V-shaped groove is bent, so that A structure of a steion tab that can be easily opened by inserting a finger deeply is described.
Further, Patent Document 2 describes a can lid opening tab in which a bending groove is provided on the upper surface so as to cross the entire width of the tab between an attachment portion attached to a rivet of the can lid body and a finger hook portion. ing.

JP 2000-128167 A JP 2003-54548 A

The following problems remain in the conventional technology.
If the bending groove is simply formed on the upper surface of the tab as in the above prior art, it is necessary to first fold the groove by hooking a finger or a nail to the end of the tail and pulling it up to cause the tab. There was also a risk of damaging the nails. In addition, when a bending groove is formed between the center portion of the tab, that is, the attachment portion to the rivet and the finger hooking hole, the tail portion is bent up by the bending groove, but the center portion of the tab is bent. There was a problem that it was difficult to apply torque and difficult to open.
For this reason, in a canon tab type can lid, it is conceivable to tip up the tail portion of the tab in advance in order to improve the finger-holding property to the tab. However, if tip-up is applied before the can lid is wrapped around the can body, when the can lid is stacked and transported, the tab contacts the inner surface of the stacked can lid, and the molding oil of the tab adheres to the inner surface. There was an inconvenience. Further, there is a problem that a gap is generated in the overlap of the can lids, resulting in an accordion-like state, and the conveyance becomes unstable.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide a can manufacturing method capable of manufacturing a can having a tail portion tipped up without any hindrance to transport of the can lid. .

  The present invention employs the following configuration in order to solve the above problems. That is, the method for manufacturing a can according to the first invention includes a can lid provided with a can lid main body and a can lid tab attached to the upper surface of the can lid main body. A can manufacturing method comprising a step, wherein the can lid tab is attached to a rivet formed to protrude from the upper surface of the can lid body, and an opening defined by a score in the can lid body A tip portion that is overlaid on the piece, and a tail portion that extends in a direction opposite to the tip portion with respect to the attachment portion, and the tail portion is bent after the tightening step to It has the tab bending process which floats up from the disk-shaped panel part arrange | positioned at the center part of the said can lid main body, It is characterized by the above-mentioned.

  This can manufacturing method has a tab folding step of bending the tail portion and lifting the end of the tail portion upward from the disk-shaped panel portion arranged in the central portion of the can lid body after the winding and tightening step. Therefore, when manufacturing cans with floating tails, the tails are not bent before tightening. It does not occur and stable conveyance becomes possible.

According to a second aspect of the present invention, there is provided a can manufacturing method according to the first aspect, wherein the tail portion includes a finger hook hole formed in an intermediate portion, and the tail portion is formed on both sides of the finger hook hole in the tab folding step. It is characterized by bending.
That is, in this can manufacturing method, since the tail portion is bent on both sides of the finger hooking hole in the tab folding step, the torque is easily applied and easily opened when the can is opened.

  According to a third aspect of the present invention, there is provided a can manufacturing method according to the second aspect, wherein the tail portion is formed by bending and bending the peripheral portion to the lower surface side which is the can lid main body side, A pair of non-curl portions in which the curl portion is not formed in a portion facing the finger hooking hole, and the thickness gradually increases toward both sides of the non-curl portion of the curl portion toward the non-curl portion. A thin fold portion is formed, and a non-curled portion and the thin fold portions on both sides thereof are formed with a mountain-shaped recess on the lower surface side, and the winding process is performed on the opening of the can body It has a can lid pressing step of pressing the covered can lid from above with a can lid support, and the tab bending step is performed by a protrusion provided on the lower surface of the can lid support at the time of the can lid pressing step. Opposite the recess of the can lid tab The top portion is pressed downward and is characterized by floating the end of the tail portion as a starting point the recessed portion by bending the tail portions upward from the panel section.

That is, in this method of manufacturing a can, the tab bending step is such that the upper surface portion facing the dent portion of the can lid tab is directed downward by the protrusion provided on the lower surface of the can lid supporter during the can lid pressing step. The tail part is bent starting from the dent part and the end part of the tail part is lifted upward from the panel part, so the upper part of the dent part is pressed by the protrusion provided on the knockout pad of the can lid supporter. By doing so, the tail portion is bent at the recessed portion, and the end side of the tail portion can be easily chipped up. That is, there is a mountain-shaped gap between the upper surface of the can lid body and the recessed portion, but when the upper part of the recessed portion is pressed by the protrusion, it is bent so as to crush the mountain-shaped gap, and the end of the tail portion The part is in a state of being chipped up before pressing. Moreover, since it bends in the recessed part in the both sides of a finger hooking hole, it is easy to apply a torque at the time of can opening, and it becomes easy to open.
In addition, when there is no said thin folding part and a dent part is not a mountain shape but a narrow rectangular shape, even if the opposing upper surface of a dent part is pressed, it is difficult to bend and it is difficult to tip up a tail part.

The method for producing a can according to a fourth invention is characterized in that, in the third invention, the width of the portion folded back on the back surface side of the thin fold portion is gradually narrowed toward the non-curl portion. And
That is, in this method for manufacturing a can, the width of the portion folded back on the back side of the thin fold portion is gradually narrowed toward the non-curl portion, so that the strength becomes stronger as the thin fold portion becomes closer to the non-curl portion. By being lowered, it can be easily bent at the depression with the non-curled portion as the top during pressing.

The present invention has the following effects.
That is, according to the method for manufacturing a can according to the present invention, after the tightening step, the tail portion is bent and the end portion of the tail portion is directed upward from the disk-shaped panel portion disposed in the central portion of the can lid body. Because it has a tab folding process that floats, when manufacturing cans with the tail end floating, the tail is not tipped up before tightening, and the tab is used when the can lid is stacked and transported. Are not in contact with each other, and no gap is formed in the overlap, thereby enabling stable conveyance.
In this way, before the can lid is wrapped around the can body, the tail portion is not tipped up, and good transportability and the like are obtained, and the tail portion is tipped up with the can lid wrapped around the can body. Therefore, the fingertip can be easily applied to the end portion of the tail portion, and can be easily opened even with a weak force without damaging the nails than in the past.

In one Embodiment of the manufacturing method of the can which concerns on this invention, it is an expanded sectional view of the principal part which shows the press by the projection part of a knockout pad. In this embodiment, it is an expanded sectional view of the principal part which shows the state which the knockout pad contacted the can lid and the chuck member fitted. In this embodiment, it is a side view which shows the tab for can lids. In this embodiment, it is the top view (a) and bottom view (b) which show the tab for can lids. In this embodiment, it is the top view (a) and AA sectional view (b) which show a can lid. In this embodiment, they are the top view (a) and bottom view (b) which show the tab for can lids which developed. In this embodiment, it is sectional drawing which shows a tab bending process in order of a process. In this embodiment, it is sectional drawing which shows the state which is winding the can lid around the can body with the can winding apparatus. In this embodiment, it is the front view which showed roughly a set of winding unit in a can winding apparatus.

  Hereinafter, an embodiment of a method for producing a can according to the present invention will be described with reference to FIGS. 1 to 9.

As shown in FIGS. 8 and 9, the can manufacturing method of the present embodiment includes a can lid 20 including a can lid body 2 and a can lid tab 1 attached to the upper surface of the can lid body 2. This is a manufacturing method of a can having a winding process of winding around an opening of a trunk 121.
As shown in FIGS. 3 to 5, the can lid tab 1 includes a mounting portion 4 attached to a rivet 3 that protrudes from the upper surface of the can lid body 2, and a score (main score 5 a) on the can lid body 2. ) And a tail portion 8 extending in a direction opposite to the tip portion 7 with respect to the attachment portion 4.
The tail portion 8 includes a finger hooking hole 8a formed in the intermediate portion. This finger hooking hole 8 a has a long hole shape having a long axis in a direction orthogonal to the direction from the tip portion 7 to the end portion of the tail portion 8.

Further, the tail portion 8 is formed with a curled portion 9 formed by being folded back and bent to the lower surface side which is the can lid main body 2 side at the peripheral portion, and a curled portion 9 is formed at a portion facing both sides of the finger hooking hole 8a. A pair of non-curled portions 10 that are not provided.
Thin folds 9 a whose thickness gradually decreases toward the non-curl part 10 are formed on both sides of the curl part 9.

The non-curled portion 10 and the thin folded portions 9a on both sides thereof are formed with a mountain-shaped recess portion 11 on the lower surface side.
Further, the width of the portion folded back on the back surface side of the thin fold portion 9 a is gradually narrowed toward the non-curl portion 10. That is, the folded portion of the thin folded portion 9 a is tapered toward the non-curled portion 10.

  The can lid body 2 has a disk-shaped panel portion 20a disposed in the center portion thereof, and a counter that forms an annular concave portion 22 that continues from the outer peripheral edge of the panel portion 20a through the corner portion 21 and faces downward. Continuous to the sink portion 23, the chuck wall portion 24 extending from the outer peripheral edge of the counter sink portion 23 while increasing in diameter upward, the shoulder portion 25 continuing from the outer peripheral edge of the chuck wall portion 24, and the shoulder portion 25. And a curled outer peripheral portion 26.

A rivet 3 is formed on the upper surface of the panel portion 20a so as to protrude from the center of the panel portion 20a, and a can lid tab 1 is attached to the rivet 3. Further, an opening piece 6 defined by the score portion 40 is formed in a portion extending in a specific radial direction from the rivet 3 on the upper surface of the panel portion 20a (on the left side of the rivet 3 in FIG. 5). A finger hook recess 26 is formed on the opposite side (the right side of the rivet 3 in FIG. 5).
A concave panel deboss 20b is formed so as to surround the opening piece 6 and the finger rest 26.

  The score portion 40 includes a start end portion 41, an arc-shaped portion 42 that is an arc-shaped initial fracture portion that substantially halves the rivet 3, a substantially elliptical intermediate portion 43, and a terminal end portion 44. And the terminal portion 44, leaving a part of the connecting portion 45 to the panel portion 20 a to define the opening piece 6. The arc-shaped portion 42 is formed in a ring-shaped coined portion that is crushed by coining around the rivet 3.

Moreover, the score part 40 was provided with the main score 5a which is fractured | ruptured by the press by the tab 1 for can lids, and forms the opening piece 6, and the auxiliary score 5b formed in parallel adjacent to the inside of the main score 5a. The main score 5 a and the auxiliary score 5 b are connected at the start end 41 and the end end 44 of the score portion 40.
And the auxiliary | assistant score 5b is formed shallower than the adjacent main score 5a, and becomes a structure which is not fractured | ruptured by the press of the tab 1 for can lids.
In addition, the main score 5a of this embodiment here corresponds to the score in this invention.

On the opening piece 6, an inner bead 28 is formed so as to protrude along the score portion 40, thereby reinforcing the opening piece 6.
When pulling up the tail 8 end of the can lid tab 1, the finger hook recess 26 is arranged to facilitate the lifting by placing a fingertip below the end, and a panel near the bottom of the tail 8 end. The portion 20a is formed radially outward.
The rivet 3 is formed by applying a coining process in which the periphery of the center of the panel part 20a is pressed in a ring shape from above to project the center part of the panel part 20a upward.

  The tab 1 for the can lid is formed flat by cutting out a metal plate such as aluminum and pressing it or the like, and as described above, the tip 7 and the rivet 3 arranged above the opening piece 6 are arranged. The tail portion 8 is formed on the opposite side with respect to the finger portion, and the tail portion 8 is formed with a finger hooking hole 8a which is a tab hole opening in the thickness direction of the can lid tab 1. A tongue portion 34 is formed by a U-shaped slot 34 a between the tip portion 7 and the tail portion 8, and a mounting portion 4 that is a rivet hole is formed in the tongue portion 34. The can lid tab 1 is attached in a state where 3 is inserted and the lower surface of the tongue 34 is in contact with the surface of the panel deboss 20b.

Further, the can lid tab 1 has a curled portion 9 formed by curling a metal plate on the lower surface side at the outer peripheral edge of the whole except the non-curled portion 10 or the inner peripheral edge of the finger hooking hole 8a. The overall rigidity is improved. A development view before the curled portion 9 is bent is shown in FIG.
As shown in FIG. 6, the end of the tail portion 8 of the can lid tab 1 is formed by bending the outer peripheral edge, and a flat portion 32a orthogonal to the longitudinal direction of the can lid tab 1 is formed at the end edge. Is formed.

In the can manufacturing method of the present embodiment, the tail portion 8 is bent and the end portion of the tail portion 8 is disposed above the disc-shaped panel portion 20a disposed at the center portion of the can lid body 2 after the winding step. It has a tab folding process to float on.
In this tab folding step, the tail portion 8 is bent on both sides of the finger hooking hole 8a. That is, the tail portion 8 is bent on both sides of the finger hooking hole 8a on the long axis direction side.
The tightening step includes a can lid pressing step in which the can lid 20 covered on the opening of the can body 121 is pressed from above by the can lid support 133.
As shown in FIGS. 1 and 9, the tab bending step faces the recess 11 of the can lid tab 1 by a protrusion P provided on the lower surface of the can lid support 133 in the can lid pressing step. The upper surface portion is pressed downward, the tail portion 8 is bent starting from the recessed portion 11, and the end portion of the tail portion 8 is floated upward from the panel portion 20 a of the can lid body 2.

  At this time, the tail portion 8 is bent so that the end portion of the tail portion 8 does not float above the upper ends of the shoulder portion 25 and the curl outer peripheral portion 26. That is, the tail portion 8 is bent so that the end portion is disposed within the range from the upper surface of the panel portion 20 a to the upper ends of the shoulder portion 25 and the curl outer peripheral portion 26. This is to prevent the end portion of the tail portion 8 from floating too much, and the end portion of the tail portion 8 from being caught by another object during handling such as transporting, and so on.

  A can body 121 around which the can lid 20 is wound is a neck portion 123 having a diameter reduced from an opening end portion of a bottomed cylindrical body portion 122 formed by drawing and ironing (DI processing) an aluminum alloy plate material. And an outward flange portion 124 is formed continuously at the upper end of the neck portion 123.

And the can winding apparatus for winding up this can body 121 and the can lid 20 is comprised as shown in FIG.
The can winding device 131 includes a lifter 132 that is mounted on a turret of a tightening machine body (not shown) and is driven to move up and down and rotated, and a can lid 20 that covers the can body 121 from above. A can lid support 133 that is disposed inside the can lid 20 while pressing, and a can body 121 and a can lid 20 that are rotated between the can lid support 133 and the lifter 132 while being held radially outward. A plurality of sets of winding fastening units, each of which is a combination of a plurality of seaming rolls 134 and 135 that perform winding fastening by approaching from one direction, are provided at intervals in the circumferential direction.

  The lifter 132, the can lid support 133 and the seaming rolls 134 and 135 move between the lifter 132 and the can lid support 133 while moving in the circumferential direction by the turning of the turret of the winder main body. 121 and the can lid 20 are received and are sandwiched between them, and wound with seaming rolls 134 and 135. FIG. 9 shows only one set of the winding unit including the lifter 132, the can lid support 133 and the seaming rolls 134 and 135.

  The lifter 132 includes a lifter plate 136 on which the can body 121 is placed, and a holder portion 137 that holds a spring or the like that biases the lifter plate 136 upward, and rotates together with the turret of the winder body. As a result, it moves up and down as indicated by arrow A while moving along a ring-shaped cam (not shown) fixed to the tightening machine body, and rotates around its own axis X as indicated by arrow B1. It is the structure which is made.

  The can lid support 133 includes a knockout pad 141 that holds the can lid 20 from above, and is disposed around the knockout pad 141 on the same axis as the knockout pad 141 and is located on the inner peripheral surface side of the chuck wall 106 of the can lid 20. And a chuck member 142 that supports the lifter 132 and is disposed on the same axis as the lifter 132. Therefore, the lifter 132, the knockout pad 141 of the can lid support tool 133, and the chuck member 142 are disposed on the same axis X.

  As shown in a part of the enlarged view in FIG. 2, the chuck member 142 applies a pressing force applied to the outer peripheral surface thereof from the seaming rolls 134 and 135 toward the inner side in the radial direction during the tightening. A wall support surface 143 that is supported inside the chuck wall 106 is formed at an inclination angle of, for example, 4 ° in a direction in which the diameter gradually increases as it goes upward with respect to the axis X of the chuck member 142, and the wall support surface 143. An annular projecting portion 144 that fits into the counter sink portion 105 of the can lid 20 is formed below, and a recessed portion 145 for accommodating the knockout pad 141 is formed inside the annular projecting portion 144. The chuck member 142 is rotatably supported at its upper part by the turret of the winding machine body, and the pinion gear engages with the rack of the winding machine body as the turret turns, and the arrow in FIG. As shown by B2, it is rotationally driven.

  The knockout pad 141 includes a support shaft 146 (see FIG. 8) disposed on the axis X of the chuck member 142 so as to be vertically movable, a horizontal disc portion 147 fixed to the tip of the support shaft 146, and It is comprised from the taper-shaped cylinder part 148 integrally formed in the outer peripheral part of the disc part 147. As shown in FIG. The support shaft 146 is supported so as to be rotatable about the axis X, and is moved up and down by the cam of the winder main body via the rod (not shown) as the turret rotates as described above. A position where the disc portion 147 of the knockout pad 141 is accommodated in the recess 145 of the chuck member 142 (see FIG. 8A), and a position where the disc portion 147 protrudes downward from the tip of the annular protrusion 144 (FIG. 8B). (See below).

  As shown in FIG. 1, a protrusion P is provided on the lower surface of the can lid support 133. That is, in the knockout pad 141 of the can lid support 133, a protrusion P that extends in an annular shape and protrudes downward is formed on the lower surface of the disc portion 147. As shown in FIG. 7, the protruding portion P is provided at a position where the upper surface portion facing the recessed portion 11 of the can lid tab 1 can be pressed downward.

  When the can lid 20 is tightened on the can body 121 by the can tightening device 131 configured as described above, the can body 121 is sequentially supplied to each lifter 132 swung by the turret and placed on the lifter 132. As shown in FIG. 8 (a), the can lid 20 is supplied one by one on the flange portion 124 of the can body 121 in a closed state, and nitrogen gas is supplied to the head space portion in the can body 121, After the internal air is replaced with nitrogen gas, the knockout pad 141 is lowered to press the panel portion 20a of the can lid 20 from above as shown in FIG.

  At this time, as shown in FIG. 7, the protrusion P of the knockout pad 141 presses the upper surface portion facing the recessed portion 11 of the can lid tab 1 downward, and the tail portion starts from the recessed portion 11. 8 is bent and the end portion of the tail portion 8 is lifted upward from the panel portion 20a of the can lid body 2. That is, when the protruding portion P pushes both sides of the finger hooking hole 8 a on the upper surface of the recessed portion 11, the tail portion 8 is bent and the end portion is lifted away from the can lid body 2.

  Next, as shown in FIG. 8B, from the state where the can lid 20 is pressed by the knockout pad 141, the lifter 132 and the knockout pad 141 rise to push up the can body 121 and the can lid 20, As shown in FIG. 2C and FIG. 2, the can sink 20 is gripped by fitting the counter sink portion 105 of the can lid 20 to the annular projecting portion 144 of the chuck member 142. When the chuck member 142 is fitted, the can lid 20 and the knockout pad 141 are aligned with each other, so that the annular protrusion 144 of the chuck member 142 is smoothly and smoothly inserted into the annular recess 104 of the counter sink portion 105 of the can lid 20. Guidance is accurate and there is no occurrence of contact with one piece.

Next, the seaming rolls 134 and 135 wind up the flange 124 and the can lid 20 of the can body 121 to form the tightening portion 157, and then the lifter 132 descends, as shown in FIG. Thus, the chuck member 142 is separated from the can lid 20. At this time, the knockout pad 141 is in a state in which the can lid 20 is pressed, and then the lifter 132 is further lowered and the knockout pad 141 is also returned into the recess 145 of the chuck member 142.
In this series of winding processes, the knock-out pad 141 accurately aligns the can lid 20, so that uniform winding can be performed in the circumferential direction, and variations in the winding dimensions can be prevented. .

As described above, in the present embodiment, as shown in FIG. 7A, the can lid tab 1 having the recess 11 formed on the lower surface is attached to the rivet 3 of the can lid body 2. The can body 121 is tightened. At this time, as shown in FIG. 7B, the depression 11 of the tab 1 for can lid is pressed from above with the projection P of the knockout pad 141 toward the can lid body 2 side, as shown in FIG. ), The upper surface portion opposed to the recessed portion 11 is recessed, and the end portion of the tail portion 8 is chipped up.
In addition, you may chip up the edge part of the tail part 8 by pressing the upper part of the dent part 11 using a dedicated press machine between the process after winding and packing process.

  As described above, the can manufacturing method according to the present embodiment includes a tab bending step in which the tail portion 8 is bent and the end portion of the tail portion 8 is lifted upward from the panel portion 20a of the can lid body 2 after the tightening step. Therefore, when manufacturing a can in which the end portion of the tail portion 8 is floated, the tail portion 8 is not bent before tightening, so that the tab 1 does not come into contact with the can lid 20 when it is transported in a stacked manner. There is no gap in the overlap, and stable conveyance is possible.

In addition, since the tail portion 8 is bent on both sides of the finger hooking hole 8a in the tab folding step, it is easy to apply torque at the time of opening the can by opening the finger hooking hole 8a.
Furthermore, the tab bending step presses the upper surface portion facing the recess 11 of the can lid tab 1 downward by the projection P provided on the lower surface of the can lid support 133 during the can lid pressing step. Since the tail portion 8 is bent starting from the recessed portion 11 and the end portion of the tail portion 8 is lifted upward from the panel portion 20a of the can lid main body 2, the protrusion provided on the knockout pad 141 or the like of the can lid support 133 By pressing the upper portion of the recessed portion 11 with the portion P, the tail portion 8 is bent at the recessed portion 11, and the end side of the tail portion 8 can be easily chipped up.

  That is, a mountain-shaped gap is interposed between the upper surface of the can lid body 2 and the recessed portion 11, but when the upper portion of the recessed portion 11 is pressed by the protrusion P, it is bent so as to crush the mountain-shaped gap. The end part of the tail part 8 is in a state of being tipped up before being pressed. Moreover, since it bends in the recessed part 11 in the both sides of the finger hooking hole 8a, it is easy to apply torque at the time of can opening, and it becomes easy to open.

  The technical scope of the present invention is not limited to the above embodiment, and various modifications can be made without departing from the spirit of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Tab for can lids, 2 ... Main body of can lid, 3 ... Rivet, 4 ... Attachment part, 5a ... Main score, 6 ... Opening piece, 7 ... Tip part, 8 ... Tail part, 8a ... Finger hook hole, 9 ... Curl Part, 9a ... thin fold part, 10 ... non-curl part, 20 ... can lid, 121 ... can body, 133 ... can lid support, P ... projection part

Claims (4)

A can manufacturing method comprising a winding step of winding a can lid provided with a can lid main body and a can lid tab attached to the upper surface of the can lid main body to an opening of the can body,
The can lid tab is attached to a rivet formed to protrude from the upper surface of the can lid body, a tip portion overlaid on the opening piece defined by the score on the can lid body, A tail portion extending in a direction opposite to the tip portion with respect to the attachment portion,
After the tightening step, it has a tab bending step in which the tail portion is bent and the end portion of the tail portion is floated upward from the disk-shaped panel portion arranged in the central portion of the can lid body. A method for producing a can characterized by the above. In the manufacturing method of the can of Claim 1,
The tail portion includes a finger hole formed in an intermediate portion,
A can manufacturing method, wherein the tail portion is bent on both sides of the finger hooking hole in the tab folding step. In the manufacturing method of the can of Claim 2,
The tail part is a curled part formed by folding back and bending to the lower surface side which is the can lid body side at the peripheral part,
A pair of non-curled portions in which the curled portions are not formed in the portions facing the finger hooking holes on both sides,
A thin fold portion having a thickness gradually reduced toward the non-curl portion is formed on both sides of the non-curl portion of the curl portion,
With the non-curl portion and the thin fold portions on both sides thereof, a mountain-shaped recess is formed on the lower surface side,
The winding and tightening step includes a can lid pressing step of pressing the can lid covered on the opening of the can body from above with a can lid support.
The tab bending step, at the time of the can lid pressing step, presses the upper surface portion facing the dent portion of the can lid tab downward by a projection provided on the lower surface of the can lid support, A method for manufacturing a can, characterized in that the tail portion is bent starting from the recess and the end of the tail portion is floated upward from the panel portion. In the manufacturing method of the can of Claim 3,
The method of manufacturing a can according to claim 1, wherein a width of a portion of the thin folded portion that is folded back is gradually narrowed toward the non-curled portion.

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