JP2007136538A - Ring end manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a ring end manufacturing method for manufacturing a ring end having a wide opening part, with which disposal of blanked scraps for forming the opening part is eliminated and the material use efficiency is enhanced. <P>SOLUTION: In the ring end manufacturing method: a metallic plate is blanked in a circular shape to form a cylinder 13 with a bottom; a bead 13a is formed around the barrel wall of the cylinder 13; the cylinder is cross-sectioned in parallel with the bead 13a at the ridge position 13b and the valley position 13c of the bead 13a to form a tubular member 20, and the inner circumferential end 20a of the tubular member 20 is press-fitted downwardly. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a method for manufacturing a ring end provided with a wide opening for bonding a seal member to form a can lid, and more specifically, a large opening area used in the fields of tuna, pet food, powdered milk and the like. The present invention relates to a method of manufacturing a ring end provided on a can lid that is opened by peeling off a sealing member on the top surface as a full open lid.

Conventionally, as a lid for canning that can be easily opened, as an opening (extraction port) provided on a can lid panel surface (top flat portion) of a metal can, a narrow-mouth type that is mainly used for beverages Wide-mouth types are widely used for solid contents such as canned foods.
As a method of opening the opening portions of these can lid panel surfaces, a cut groove called a score is inserted into the shape of the opening portion, and the groove is torn and opened.

Further, as other types of opening methods, can lids disclosed in Japanese Utility Model Laid-Open No. 62-108229 (Patent Document 1) and Japanese Patent Laid-Open No. 8-11881 (Patent Document 2) are known.
As shown in FIG. 6, this type of can lid is provided with a tightening portion 62 for tightening around a can container 61 at an outer peripheral edge, and an opening 64 is provided in a panel portion 63 surrounded by the tightening portion 62. The ring end 65 is formed and a seal member 66 that seals the opening 64 in a peelable manner. The seal member 66 is heat-sealed by the panel 63 of the ring end 65 to seal the opening 64. To do.

In such a conventional can lid, the ring end 65 is manufactured by the method shown in FIG. That is, first, as shown in FIG. 7 (c), the circular metal plate 71 (FIG. 7 (a)), which is a material, is formed with a winding portion 74a at the periphery thereof as shown in FIG. 7 (b). Then, the panel surface 72 is punched and removed to provide an opening 64. The ring end 65 is manufactured by discarding the circular plate 72a that has been punched and scrapped.
Further, as shown in FIG. 7D, a seal member 75 is heat-sealed (heat-pressed) on the opening 64 formed by punching the panel surface 72 of the ring end 65 and sealed to obtain a can lid.
Here, the ring end is a ring-shaped member that constitutes a lid of the can, and includes a panel portion having an opening, and a tightening portion that joins the can body at the periphery of the panel portion. Sealing is performed with a sealing member, and a winding end of a ring end is wound around the mouth of the can body to form a can lid.
Japanese Utility Model Publication No. 62-108229 JP-A-8-11881

As described above, in the method of manufacturing a ring end from a circular metal plate, the circular plate formed by punching the panel surface to form an opening is discarded as scrap, and the utilization efficiency of the material is extremely low. Was holding.
An object of the present invention is to solve the above-described conventional problems, and to manufacture a ring end having a wide-mouth opening with high material utilization efficiency and to reduce the manufacturing cost of the can as a whole.

In the ring end manufacturing method according to claim 1, a bottomed cylinder 13 is formed by punching a metal plate in a circular shape, a bead 13 a is formed around the body wall of the bottomed cylinder 13, and a peak portion position 13 b of the bead 13 a is formed. And it cuts and cuts in parallel with bead 13a in trough part position 13c, forms tubular member 20, and press-fits inner peripheral end 20a of tubular member 20 below.
The ring end manufacturing method according to claim 2, wherein a bottomed cylinder 13 is formed by punching a metal plate in a circular shape, a bead 13 a is formed around the body wall of the bottomed cylinder 13, and a peak position 13 b of the bead 13 a is formed. And at the valley part position 13c, the ring member is cut in parallel with the bead 13a, the tubular member 20 is formed, the inner peripheral end 20a of the tubular member 20 is press-fitted downward, and at the same time, the inner peripheral end 20a is bent upward and the inner peripheral edge 42, and the outer peripheral end portion 20b of the tubular member 20 is bent slightly downward to form a winding portion 41 of the ring end 40.
The ring end manufacturing method according to claim 3 is characterized in that, in claim 1 or 2, the bottomed cylinder 13 is formed by a DI molding method.
The ring end manufacturing method according to claim 4 is a method of winding a rectangular metal plate 31 to form a round molded material 33, welding the overlapped portion by welding to form a bottomless cylinder 37, and surrounding the body wall of the cylinder 37 The bead 13a is formed in the bead 13a, and the bead 13a is cut at the peak position 13b and the valley position 13c in parallel with the bead 13a to form the tubular member 20, and the inner peripheral end 20a of the tubular member 20 is press-fitted downward. It is characterized by that.
In the ring end manufacturing method according to claim 5, the rectangular metal plate 31 is wound to form a round molded material 33, and the overlapped portion is welded to form a bottomless cylinder 37, and the periphery of the cylinder wall of the cylinder 37 When the bead 13a is formed, and the bead 13a is cut at the crest portion 13b and the valley portion 13c in parallel with the bead 13a to form the tubular member 20, and the inner peripheral end portion 20a of the tubular member 20 is press-fitted downward. At the same time, the inner peripheral end portion 20a is bent upward to form the inner peripheral edge 42, and the outer peripheral end portion 20b of the tubular member 20 is bent slightly downward to form the tightening portion 41 of the ring end 40.

  According to the present invention, in the manufacture of a ring end having a wide-mouthed opening on the panel surface, it is not necessary to punch and cut most of the material plate in order to provide the opening, thereby significantly increasing the material yield. This can reduce the manufacturing cost of the entire can.

Embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an explanatory view of a drawing / ironing process for obtaining a bottomed cylinder, where (a) illustrates the initial stage of ironing and (b) illustrates the final stage of ironing.
FIG. 2 is an explanatory view (a) of a bead processing step and an explanatory view (b) of a step of cutting a tubular member from a beaded bottomed cylinder. FIG. 3 is an explanatory view of a welding joining process for obtaining a cylindrical body. 4A and 4B are explanatory views of a process of forming a ring end from a tubular member, in which FIG. 4A is a plan view and FIG. 4B is an AA cross-sectional view of FIG. FIG. 5: is a top view (a) which shows the aspect which sealed the sealing member at the ring end, BB sectional drawing (b), and the elements on larger scale (c).

(Forming a bottomed cylinder)
An embodiment for obtaining a bottomed cylinder will be described with reference to FIG. First, a metal plate is punched into a circular shape, and a bottomed cylinder is formed from the circular material. As a method for forming a bottomed cylinder, known techniques such as drawing, redrawing (DR molding), bending / drawing redrawing and ironing can be used, and DI, which is widely used as a method for producing carbonated beverages and the like. A molding method (Draw & Ironing) is preferred.
In the DI molding method, first, a circular material is drawn at a drawing ratio (diameter of circular material / diameter after drawing) of about 1.9 to 2.5 times to obtain a drawn cup 17, and the drawn cup 17 is re-used. Set between the squeezing die 11 and the heel holding sleeve 10.

Next, the circular punch 10a is pushed from the center hole of the reed holding sleeve 10 and redrawn with the redrawing die 11 to form a redrawn bottomed can.
Subsequently, the redrawn bottomed can is passed through the first ironing ring 12a, the second ironing ring 12b, and the third ironing ring 12c, and the can body wall of the redrawn bottomed can is ironed and sequentially thinned. The bottomed cylinder 13 is used.
In the ironing process, the can body wall is forcibly thinned and ironed by placing the first to third three-stage ironing rings in advance so that the inner diameters of the first and third three-stage ironing rings become smaller in order. It can be reduced to about 1/3.
However, in the present invention, as will be described later, since the bottom of the can that is not thinned is discarded, the effect of making the thickness in the height direction uniform is more important, and the change from the material plate thickness is 1/1 to It may be about 2/3.

(Bead processing)
Next, as shown in FIG. 2A, the inner and outer surfaces of the cylinder wall of the bottomed cylinder 13 formed by the DI molding method described above are brought into contact with the inner roller 21 and the outer roller 22 and rotated to rotate the bottomed cylinder. A wave-like bead 13a is formed around the 13 body walls in a sectional view.
The bead 13a has a corrugated pattern in which the large diameter portion and the small diameter portion are alternately repeated in the height direction of the bottomed cylinder 13.

Next, the beaded bottomed cylinder 13 is cut into a ring parallel to the bead 13a to form a plurality of truncated cone-shaped tubular members 20. That is, as shown in FIG. 2 (b), the bottomed cylinder 13 on which the beads 13a are formed is cut in a circle in parallel to the beads 13a at the peak positions 13b and the valley positions 13c of the beads 13a. Six tubular members 20 are formed.
Since the bottomed cylinder formed by the DI molding method has ears formed at the can bottom and the opening periphery, the bottom can bottom 24 and the top opening periphery 23 are discarded as scrap. Similarly, when the bottomed cylinder is formed by DR molding or the like, the bottom of the can and the peripheral edge of the opening are discarded.

Further, instead of the DI molding method, a rectangular metal plate can be rounded, and the joint can be seam welded to form a bottomless cylinder. That is, as shown in FIG. 3, a rectangular metal plate 31 is wound so as to wrap the inner core 32 of the welding machine to form a round molding material 33 having an overlapping portion, and an upper electrode 34 and a lower electrode 35 are formed on the overlapping portion. A bottomless cylindrical body 37 having a welded joint 36 is formed by contact, energization, and seam welding by resistance heating.
In addition, since the bottom and the ear | edge are not formed in the cylinder formed by the welding method, the cutting | disconnection of a can bottom part and an opening peripheral part is unnecessary.

Next, the process of shape | molding the ring end 40 from the tubular member 20 is demonstrated using FIG. In the steps (1) to (5) in which the tubular member 20 is pressed using two upper and lower molds,
First, in step (1), the inner peripheral end 20a of the tubular member 20 is press-fitted downward, and at the same time, the inner peripheral end 20a is bent upward to form the inner peripheral edge 42 of the ring end 40. The end portion 20b is bent slightly downward to form a tightening portion 41 of the ring end 40.
In the step (1), the inner peripheral end portion 20a is press-fitted downward, the inner peripheral end portion 20a is bent upward to form the inner peripheral edge 42, and the outer peripheral end portion 20b is bent slightly downward to be the tightening portion 41. The process may be formed in multiple stages.
Next, in the step (2), the shape of the tightening portion 41 and the inner peripheral edge 42 of the ring end 40 is adjusted, and in the steps (3) and (4), the end of the inner peripheral edge 42 is wound upward and outward to bend the inner edge. The curled portion 43 is used.

Further, in step (5), the upper surface of the inner edge curl portion 43 protruding upward from the surface position of the panel portion 44 of the ring end 40 is press-fitted downward to form a flat panel surface 46 around the opening 45. To do. The opening 45 is formed substantially concentrically with the panel portion 44, and the size thereof is preferably substantially the entire surface of the panel portion leaving an adhesion surface with a seal member 50 described later.
By press-fitting the upper surface of the inner edge curl portion 43 in the step (5), the plate material cut portion exposed at the time of cutting the tubular member 20 by cutting the ring is brought into contact with the panel portion 44 and concealed to prevent danger due to a sharp end surface. Can do.

Next, the seal member 50 is heat-sealed (thermocompression bonded) to the opening 45 of the ring end 40 processed in the process of FIG.
FIG. 5A is a plan view of a lid member 48 in which the seal member 50 is heat-sealed to the ring end 40, and FIG. (C) is a partially enlarged cross-sectional view of the peripheral edge of (b).
The sealing member 50 can be thermocompression-bonded by preliminarily applying an organic film layer or a coating adhesive layer to be heated and melted on the sealing surface, and heating the adhesion surface 47 of the panel surface 46.

Examples of the metal plate used for the ring end include an aluminum alloy plate, a tin-plated steel plate, a chromic acid-treated steel plate, a chrome-plated steel plate, and a laminated metal plate obtained by coating or laminating (laminating) an organic film on each steel plate. Are preferably used.
As the aluminum alloy plate, 1000 series, 3000 series and 5000 series alloys are preferably exemplified. A material plate thickness of 200 to 450 μm is preferably used, and the ring end plate thickness after processing is preferably 200 to 300 μm.

The gist of the present invention is that a metal plate is punched into a circular shape to form a bottomed cylinder, a bead is formed around the body wall of the bottomed cylinder, and the ring is cut in parallel to the bead at the crest and trough positions of the bead. Cutting, forming a tubular member, and press-fitting the inner peripheral end of the tubular member downward, and the technology within the same scope as such a technical idea belongs to the technical scope of the present invention. .
For example, in the above embodiment, the bead processing is performed by rotating the inner surface and outer surface of the can body in contact with the inner roller and the outer roller, but the mold is inserted into the inner and outer surfaces of the can body, and the shape of the mold is changed. It can also be formed by transferring.

  The ring end manufacturing method of the present invention solves the problem of scrap disposal of a large amount of circular material for forming the opening of the ring end, improves the material use efficiency of the material, and manufactures a wide-mouth type ring end. This contributes to material cost reduction.

It is explanatory drawing of the drawing and ironing molding process which obtains a bottomed cylinder, (a) demonstrates the initial stage of ironing, (b) demonstrates the final stage of ironing. It is explanatory drawing (a) of a bead processing process, and explanatory drawing (b) of the process of carrying out ring cutting of a tubular member from the bottomed cylinder which carried out bead processing. It is explanatory drawing of the welding joining process of obtaining a cylinder. It is explanatory drawing of the process of shape | molding a ring end from a tubular member, (a) is a top view, (b) is AA sectional drawing of (a). They are the top view (a) which shows the aspect which sealed the sealing member to the ring end, BB sectional drawing (b), and the elements on larger scale (c). It is explanatory drawing of the canning which wound the conventional ring end. It is explanatory drawing of the ring end manufacturing process which shape | molds the circular raw material by a conventional method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Reed sleeve 10a Circular punch 11 Redrawing die 12a First ironing ring 12b Second ironing ring 12c Third ironing ring 13 Bottomed cylinder 13b Mountain part position 13c Valley part 17 Squeeze cup 20 Tubular member 20a Inner peripheral edge part 20b Outer peripheral edge 21 Inner roller 22 Outer roller 23 Opening peripheral edge 24 Can bottom 31 Rectangular metal plate 32 Inner core 33 Round molding 34 Upper electrode 35 Lower electrode 36 Welded joint 37 Bottomless cylinder 40 Ring end 41 Winding part 42 Inner peripheral edge 43 Inner edge curled portion 44 Panel portion 45 Opening portion 46 Panel surface 47 Adhering surface 48 Lid material 50 Seal member

Claims (5)

A metal plate is punched into a circular shape to form a bottomed cylinder, a bead is formed around the body wall of the bottomed cylinder, and the tubular member is cut into a ring parallel to the bead at the peak and valley positions of the bead. A method of manufacturing a ring end, comprising forming and press-fitting an inner peripheral end of the tubular member downward. A metal plate is punched into a circular shape to form a bottomed cylinder, a bead is formed around the body wall of the bottomed cylinder, and the tubular member is cut into a ring parallel to the bead at the peak and valley positions of the bead. The inner peripheral end of the tubular member is press-fitted downward, and the inner peripheral end is bent upward to form the inner peripheral edge, and the outer peripheral end of the tubular member is bent slightly downward to wind the ring end. A method of manufacturing a ring end, characterized by being a fastening portion. The ring-end manufacturing method according to claim 1 or 2, wherein the bottomed cylinder is formed by a DI molding method. A rectangular metal plate is wound to form a round molded material, the overlapped portion is welded and joined to form a bottomless cylindrical body, a bead is formed around the barrel wall of the cylindrical body, and a peak position and a valley position of the bead A ring end manufacturing method comprising: cutting a ring in parallel with the bead to form a tubular member and press-fitting an inner peripheral end of the tubular member downward. A rectangular metal plate is wound to form a round molded material, the overlapped portion is welded and joined to form a bottomless cylindrical body, a bead is formed around the barrel wall of the cylindrical body, and a peak position and a valley position of the bead The tubular member is cut in parallel with the bead to form a tubular member. The inner peripheral end of the tubular member is press-fitted downward, and at the same time the inner peripheral end is bent upward to form the inner peripheral edge. A method of manufacturing a ring end, wherein the outer peripheral end portion is bent slightly downward to form a ring end winding portion.

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