JP2001179376A - Manufacturing method and device for separate can drum - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress a thermoplastic resin film to partially exfoliate in filiform when a cylindrical body with the thermoplastic resin film adhering the inside is separated in an axial direction. SOLUTION: The device comprises a couple of cutting tools that are pushed and pressed to an identical lineal domain of the both surfaces of a metal plate where the thermoplastic resin film is adhered and that conducts cutting the film and forming a groove designed for separation at the both surfaces of the metal plate, a separating outer guide 22 that is pushed and pressed to the both sides of a groove designed for separating at the outer surface of the cylindrical body 19 that is formed by folding and mating two side edges of the metal plate that is bent into curvature such that the film side shall be the inside of the plate, and a separating cutter 27 that gives a shearing load to the cylindrical body 19 along with the groove designed for separation co-acting with the separating outer guide 22.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for manufacturing a can body used for a can for filling beverages and foods, and more particularly to a method for cutting a metal cylinder along a groove to be divided. And a method and apparatus for manufacturing a plurality of can bodies.

[0002]

2. Description of the Related Art In general, a metal can is excellent in hermeticity, so that it is necessary to ensure that contents leak to the outside of the can or that outside air enters the can and comes into contact with the contents. There is an advantage that can be prevented. As such metal cans, there are a two-piece can and a three-piece can.The three-piece can has a cylindrical can body, a disc-shaped lid plate and a bottom plate, and has openings at both ends of the can body. By sealing the part, the lid plate and the bottom plate separately, the hermeticity is maintained. An example of a method and an apparatus for manufacturing a can body that can be used for manufacturing such a three-piece can is described in JP-B-6-35024.

The can body manufacturing apparatus described in this publication is
It has a turret, a cutting device, and a cutter guide. The cutter guide is formed in an arc shape, and a turret is provided at a position facing the inner wall surface.
An arc-shaped holding portion is formed on the outer periphery of the rotatable turret, and a concave groove is formed on the inner wall surface of the cutter guide in the circumferential direction. In addition, the cutting device is configured in a shaft shape, and at the tip,
An outwardly protruding cutter is formed over the entire circumference. Further, the cutting device is configured to be able to rotate between the turret and the cutter guide while revolving around the rotation axis of the turret, and to be movable in a direction parallel to the rotation axis of the turret. ing.

According to the apparatus for manufacturing a can body, a metal cylinder is supplied between the holding portion and the cutter guide, and the cutting device is moved in the direction of the central axis to be inserted into the cylinder. The cutter is pressed against the inner surface of the cylinder. Here, on the outer surface of the cylindrical body, grooves to be divided are formed in advance along the circumferential direction. In addition, the tip of the cutter has entered the concave groove. Then, in synchronization with the rotation of the turret, the cutting device rotates while revolving around the turret. In this way, when the cylindrical body rolls on the inner wall surface of the guide while being sandwiched between the cutter and the inner wall surface of the cutter guide, a shear load acts on the cylindrical body along the dividing line. Then, the cylinder is divided in the axial direction to produce a plurality of can bodies.

[0005]

However, depending on the type of contents to be sealed in the can, it is not preferable to directly contact the metal, and when the contents and the inner surface of the can come into contact with each other, There is also a possibility that the inner surface of the can is corroded. Therefore, in order to cope with such a situation, a polyester resin, a polyethylene resin, a film made of a thermoplastic resin such as a polypropylene resin is adhered to a surface of a metal plate serving as an inner surface of the metal can. In some cases, it is configured such that the inner surface does not come into contact with the contents.

As described above, when the can body of the can having the thermoplastic resin film adhered to the inner surface is manufactured by the manufacturing method and the manufacturing apparatus as described in the above-mentioned publication, first, the thermoplastic resin is cut by the cutter. As the film is cut, the cutter cuts into the cylinder and the cylinder is completely cut to produce a plurality of can bodies. That is, when completely cutting the cylindrical body, the cutter and the film strongly rub over a long area in the biting direction of the cutter. As a result, there is a possibility that a part of the cut end of the thermoplastic resin film is peeled off in the form of a thread and so-called film hair occurs. In addition, a can body is manufactured after a thermoplastic resin film on which a canned trademark or decorative pattern is printed is attached to the surface of a metal plate serving as an outer surface of the can. When the film was divided into a plurality of pieces by a cutter, there was also a possibility that film hair would occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described circumstances, and when a cylindrical body having a thermoplastic resin film adhered to at least one surface is divided in the axial direction, a part of the thermoplastic resin film is formed. It is an object of the present invention to provide a method for manufacturing a separate can body and a manufacturing apparatus for the same, which can suppress the peeling of the can in a thread shape.

[0008]

In order to achieve the above-mentioned object, a first aspect of the present invention is directed to a method in which a thermoplastic resin film is adhered to at least one surface and is divided in a circumferential direction thereof. After manufacturing a cylindrical body with grooves formed,
By applying a shear load to the cylindrical body along the planned dividing groove, the cylindrical body is divided in the axial direction to produce a plurality of can bodies. After attaching the thermoplastic resin film to at least one surface, by pressing a pair of cutting tools on the same linear region on both surfaces of the metal plate, completely cut the thermoplastic resin film, and,
The planned dividing groove for cutting a part of the metal plate is formed at opposing positions on both surfaces of the metal plate, and thereafter, the metal plate is curved and both end edges are overlapped and joined to each other, at least. After manufacturing the cylindrical body on which the thermoplastic resin film is stuck on one surface, and a groove to be divided is formed at the same position in the axial direction on the inner and outer surfaces,
From the divided grooves on one surface of the cylindrical body, the convex portions of the first cutting tool are respectively pressed on both sides separated by a predetermined distance in the axial direction of the cylindrical body, and the first
The concave portion formed between the convex portions of the cutting tool and the planned dividing groove are opposed to each other, and the contact positions of the convex portions on both sides in the axial direction of the other surface of the cylindrical body that sandwich the planned dividing groove. Also, at the position near the end portion side of the cylindrical body, pressing the receiving portion of the second cutting tool, respectively, the relief groove formed between the receiving portion of the second cutting tool and the planned dividing groove, By moving the first cutting tool and the second cutting tool relative to each other in a direction in which the convex portion enters the relief groove, along the planned dividing groove with respect to the cylindrical body. Characterized by applying a shear load.

According to a second aspect of the present invention, after manufacturing a cylindrical body having a thermoplastic resin film adhered to at least one surface thereof and having a groove to be divided in a circumferential direction thereof, the cylindrical body is formed. In a separate can body manufacturing apparatus for manufacturing a plurality of can bodies by applying a shear load along the planned dividing groove to divide the cylindrical body in the axial direction thereof, at least one surface is made of a thermoplastic resin. The film is pressed against the same linear region on both sides of the metal plate to which the film is attached, and completely cuts the thermoplastic resin film, and cuts a part of the metal plate to form a groove to be divided. A pair of cutting tools to be formed, a canning machine for manufacturing a cylindrical body by bending a metal plate on which the planned dividing groove is formed, and overlapping and joining both end edges thereof, and one of the cylindrical bodies In front of the face A first cutting tool having a convex portion pressed on both sides of the cylindrical body in the axial direction with the planned dividing groove therebetween, and a concave portion facing the planned dividing groove when the convex portion is pressed against the cylindrical body. And a receiving portion that is on both sides in the axial direction of the other surface of the cylindrical body with respect to the planned dividing groove and that is in contact with a position closer to the end of the cylindrical body than the contact position of the convex portion, After moving the first cutting tool in the radial direction of the cylindrical body and applying a shear load along the planned dividing groove to cut the cylindrical body,
A second cutting tool having a cut end of the cylindrical body and an escape groove into which the projection of the first cutting tool enters.

According to the first and second aspects of the present invention, in the step of forming the grooves to be divided on both surfaces of the metal plate, the first cutting tool and the second cutting tool are pressed against the metal plate to form the thermoplastic resin film. Since the cutting is performed completely and only a part of the metal plate is cut, the cut end of the thermoplastic resin film is hardly rubbed by the cutting tool, and therefore, film hair does not occur. Further, the cylindrical body is sandwiched between the receiving portion of the second cutting tool and the convex portion of the first cutting tool, and the direction in which the convex portion of the first cutting tool enters the concave portion of the second cutting tool. By moving the first cutting tool and the second cutting tool relative to each other, a shearing force is applied to the cylindrical body along the dividing groove to cut the cylindrical body, and the cylindrical body is cut. The end and the projection of the first cutting tool enter the relief groove. In the cylindrical body dividing step, the cut end of the thermoplastic resin film is hardly rubbed by any of the first cutting tool and the second cutting tool, so that film hair does not substantially occur.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to the drawings. FIG. 2 is a perspective view showing a configuration of a scoring device 2 for forming scores on both surfaces of the metal plate 1, and FIG. 3 is an enlarged sectional view of the metal plate 1. Metal plate 1
Has a square or rectangular planar shape. The metal plate 1 is made of, for example, an extremely thin tin-plated steel plate, a nickel-plated steel plate, or a tin-plated steel plate.
It is configured by laminating a steel sheet 3 subjected to a surface treatment, an outer layer 4 formed on one surface of the steel sheet 3, and an inner layer 5 formed on the other surface of the steel sheet 3. The outer surface layer 4 is formed by sequentially laminating a thermosetting adhesive layer 6, a printing ink layer 7, a thermoplastic resin film layer 8, and a thermosetting resin layer 9 from the steel plate 3 side. The inner surface layer 5 is configured by sequentially laminating a thermosetting adhesive layer 10 and a thermoplastic resin film layer 11 from the steel plate 3 side.

On the other hand, the scoring device 2 has an upper blank feed roll 12 and a lower blank feed roll 13 provided below the upper blank feed roll 12. The upper blank feed roll 12 and the lower blank feed roll 13 are both made of a hard metal material. This upper side blank feed roll 1
Numeral 2 is configured to be rotatable around a substantially horizontal axis (not shown), and is located at the middle of the outer peripheral surface of the upper-side blank feed roll 12 in the axial direction. A cutter 14 is formed to protrude.

In the plane including the axis of the upper blank feed roll 12, the tip shape of the upper score cutter 14, that is, the outer peripheral end shape is shown in FIG.
As shown in FIG. The angle α1 between the pair of flank surfaces 15 forming the cutting edge of the upper-side score cutter 14 can be set to, for example, about 60 degrees.

The lower side blank feed roll 13
Is configured to be rotatable about a substantially horizontal axis (not shown). The axis of the upper blank feed roll 12 and the lower blank feed roll 1
3 are arranged in parallel with each other. Further, a lower-side score cutter 16 is formed so as to protrude over the entire circumference at substantially the center of the outer peripheral surface of the lower-side blank feed roll 13 in the axial direction.

In the plane including the axis of the lower blank feed roll 13, the tip of the lower score cutter 16, that is, the outer peripheral end is formed in a substantially wedge shape as shown in FIG. Further, a pair of flank surfaces 17 forming the cutting edge of the lower side score cutter 16 are provided.
The angle β1 between them can be set to, for example, about 45 degrees. The gap A1 between the tip of the upper score cutter 14 and the tip of the lower score cutter 16 is:
The thickness is set smaller than the thickness t1 of the metal plate 1. Specifically, the gap A1 is set to be less than the thickness t2 of the steel 3. A drive mechanism (not shown) such as a motor is provided to rotate the upper blank feed roll 12 and the lower blank feed roll 13 in the directions indicated by arrows.

FIG. 1 is a perspective view showing a schematic configuration of the separating device 18. The separating device 18 includes a pair of pilots 20 and 21 and the separate outer guide 2.
And 2. The pair of pilots 20 and 21 are each formed of a metal material in a cylindrical shape, and are configured to be rotatable about a substantially horizontal same axis B1. In addition, the pair of pilots 20 and 21
It is configured to be able to revolve synchronously around the center of revolution (not shown) in a plane substantially perpendicular to the axis B1. Further, a pair of pilots 20, 21
Is configured to be rotatable around an axis B1.
Furthermore, the pair of pilots 20 and 21 are aligned with the axis B1.
Can be approached / separated along. An actuator (not shown) such as a turret, a motor, or a pneumatic cylinder is provided to control the above-described various operations of the pair of pilots 20 and 21.

Annular flanges 23, 24 are formed on the pair of pilots 20, 21, respectively. This Tsuba 23,2
The outer diameter of 4 is set larger than the inner diameter of a cylindrical body 19 described later. Further, the pair of pilots 20 and 21 have shaft portions 25 and 26 facing each other, and a separate cutter 27 is formed on the entire outer periphery of one shaft portion 26 at the end on the shaft portion 25 side. Have been. This separate cutter 27 is made of a cemented carbide. The separate cutter 27 protrudes toward the outer peripheral side of the shaft portion 26, and the outer diameter of the separate cutter 27 is set smaller than the inner diameter of the cylindrical body 19. The outer diameters of the shaft portions 25 and 26 are set to be the same, and the outer diameters of the shaft portions 25 and 26 are set smaller than the inner diameter of the cylindrical body 19.

Therefore, the shaft portions 25 and 26 are connected to the cylindrical body 1.
9 can be inserted. When the shaft portions 25 and 26 are inserted into the cylindrical body 19 and the ends of the shaft portion 25 and the shaft portion 26 are in contact with each other, the flanges 23 and 24 are located outside the cylindrical body 19. Thus, the lengths of the shaft portions 25 and 26 are set. By the way, the separate cutter 27 has such a shape that its width becomes narrower toward the distal end thereof, and the distal end of the separate cutter 27 has two convex portions 27a, 27a.
b is formed in an annular shape, and a groove (recess) 28 is formed over the entire circumference between the protrusions 27a and 27b. The width D1 of the groove 28 is wider than an inner surface score (described later) as a groove to be divided provided in the cylindrical body 19, and can be set to, for example, 0.2 mm. In addition, two convex portions 2
Flat surfaces 29 are formed at the tips of 7a and 27b, respectively.

On the other hand, the separate outer guide 22
Is provided outside the revolving region of the pair of pilots 20 and 21, and an arc-shaped guide surface 30 is formed at a portion of the separate outer guide 22 facing the revolving region of the pair of pilots 20 and 21. I have. The total arc length of the guide surface 30 is set longer than the entire circumference of the outer peripheral surface of the cylindrical member 19. The center of curvature (not shown) of the guide surface 30 and the revolving centers of the pair of pilots 20 and 21 are arranged at the same position. Further, the width C1 of the separate outer guide 22 is set shorter than the distance between the flange 23 and the flange 24 when the shaft portion 25 and the shaft portion 26 are in contact with each other.

Further, an escape groove (in other words, a concave portion) 32 is formed substantially at the center in the width direction of the guide surface 30 over the entire area in the circumferential direction. As described above, in the width direction of the separator outer guide 22, the two wide convex portions 30a and 30b and the relief groove 32 formed between the convex portions 30a and 30b are formed. This escape groove 3
The width E1 of 2 is sufficiently larger than the width of an outer surface score (described later) as a planned dividing groove formed in the cylindrical body 19, and can be set to, for example, 2.0 mm. This escape groove 32
Is set to be wider than the width F1 of the tip of the separate cutter 27 (the total width of the two convex portions 27a and 27b and the groove 28). Furthermore, both wall surfaces 33 of the groove 32
And the guide surface 30 are connected by an arc surface 34.
In the radial direction of the center of revolution of the pair of pilots 25 and 26, the positional relationship between the separate cutter 27 and the groove 32 is such that when the pair of pilots 25 and 26 revolve, the tip of the separate cutter 27 It is set to enter the inside of.

Next, a method for manufacturing the separate can body will be described. First, as shown in FIG. 2, the metal plate 1 is fed between the upper blank feed roll 12 and the lower blank feed roll 13 along two parallel side edges 1A. In this case, the metal plate 1 is arranged so that the outer layer 4 and the upper blank feed roll 12 face each other, and the inner layer 5 and the lower blank feed roll 13 face each other. In addition, the length of the other two side edges 1B is
The value is set to a value corresponding to the sum of the axial lengths of two can bodies to be manufactured.

The upper-side blank feed roll 12 and the lower-side blank feed roll 13 are each rotated in the direction of the arrow, and the metal plate 1 is separated from one of the two side edges 1B by the upper-side blank feed roll 12 and the lower-side blank feed roll 13. When entering between roll 13
As shown in FIG. 4, the upper score cutter 14 and the lower score cutter 16 are pressed against both sides of the metal plate 1 and bite into each other, whereby the formation of the outer score 35 and the inner score 36 is started.

The metal plate 1 is made up of the upper blank feed roll 12 and the lower blank feed roll 1.
3 is parallel to the two side edges 1A and almost in the middle between the two side edges 1A, the outer surface score 3
5 and an internal score 36 are formed. The outer surface score 35 and the inner surface score 36 are formed at the same location on the front and back of the metal plate 1 and in a straight line so as to connect the two side edges 1B. Further, the outer surface score 35 and the inner surface score 36 correspond to the cross-sectional shapes of the upper score cutter 14 and the lower score cutter 16,
It has a substantially V-shaped groove shape.

Here, the angle between the inclined surfaces of the outer score 35 is an angle corresponding to the angle α1 of the upper score cutter 14, and the angle between the inclined surfaces of the inner score 36 is the lower score cutter 16. This angle is equivalent to the angle β1. The outer layer 4 is completely cut by the upper score cutter 14, and the bottom of the outer score 35 reaches the steel plate 3. Further, the inner layer 5 is completely cut by the lower score cutter 16, and the bottom of the inner score 36 reaches the steel plate 3.

As described above, the outer surface score 35 is applied to the metal plate 1.
In the step of forming the inner surface score 36, the metal plate 1 is not completely cut, and the relative movement amount between the lower score cutter 16 and the metal plate 1 in the thickness direction of the metal plate 1 is relatively small. . Accordingly, in the pressing direction of the lower score cutter 16 against the metal plate 1, the length at which the cut end of the thermoplastic resin film 11 rubs against the lower score cutter 16 is relatively short, and the cut end is formed on the inner surface by the score cutter 16. Since the thermoplastic resin film 11 is pressed into the score 36, there is little possibility that a so-called film hair, in which a part of the thermoplastic resin film 11 peels off in a thread shape in this step, will occur. Upper side score cutter 1
The same applies to the formation of the outer surface score 35 by pressing the number 4.

As described above, the metal plate 1 on which the outer surface score 35 and the inner surface score 36 are formed is conveyed to a subsequent step and is rounded (curved) along the two side edges 1B into a cylindrical shape. You. In this case, the outer layer 4 is rounded so as to be on the outside. Then, the cylindrical body 19 shown in FIG. 1 is manufactured by overlapping the two side edges 1B of the rounded metal plate 1 with each other and welding (joining) by a can making machine (not shown) such as a welding machine. . As a result, an outer surface score 35 is formed on the entire outer surface of the cylindrical body 19, and an inner surface score 36 is formed on the inner surface of the cylindrical body 1. The outer surface score 35 and the inner surface score 36 are located at the same position in the axial direction of the cylindrical body 1.

Next, the cylindrical body 19 is conveyed to the separating step, and the pair of pilots 20 and 21 move in the direction approaching the axial direction, and the shaft portions 25 and 26 are inserted into the cylindrical body 19. A pair of pilots 20,
The cylindrical body 19 is held by 21. When the pair of pilots 20 and 21 revolve, the cylindrical body 19 is rotated.
Is the guide surface 3 of the separate outer guide 22
0, in other words, while being in contact with the wide convex portions 30a, 30b, the pair of pilots 20, 21 are shown by arrows F in FIG.
By rotating in the direction indicated by 1, the cylindrical body 19 rolls along the guide surface 30 in a state where the outer surface of the cylindrical body 19 is in contact with the guide surface 30. Note that a pair of pilots 2
During the revolution of 0 and 21, the movement in the axial direction is regulated by the flanges 23 and 24.

By the above operation, the outer peripheral surface of the cylindrical body 19 comes into contact with the guide surface 30, that is, the convex portions 30a, 30b, and the convex portions 27a, 27 at the tip of the separate cutter 27.
b is pressed on both sides of the inner surface score 36 of the cylindrical body 19, specifically, both sides in the axial direction of the cylindrical body 19. The contact positions of the protrusions 30a and 30b with the cylinder 19 are closer to both ends in the axial direction of the cylinder 19 than the contact positions of the protrusions 27a and 27b with the cylinder 19. In this manner, the cylindrical body 19 is sandwiched by the separate cutter 27 and the separate outer guide 22, and the projections 27 a and 27 b of the separate cutter 27 are directed toward the escape groove 32 as the cylindrical body 19 rolls. Pressed.

Then, a shear load in the thickness direction is applied to the cylindrical body 19 as follows. That is, with the rolling of the cylindrical body 19, the separation cutter 27-2
While the two convex portions 27a and 27b move in the circumferential direction of the cylindrical body 19 and press both sides of the inner surface score 36, the cylindrical body 19 is broken (cut) as shown in FIG. The projections 27a and 27b enter the clearance groove 32, and the broken end of the cylindrical body 19 is pushed and bent toward the clearance groove 32 side. The broken end of the cylindrical body 19 is curved along the arc surface 34. And the rolling cylindrical body 19
Is cut along the entire circumference, and a pair of pilots 25 and 26 are axially separated from each other to form a single cylindrical body 19.
Are removed from the pair of pilots 25 and 26, specifically, two can bodies 37 and 38 divided in the axial direction.

In the step of dividing the cylindrical body 19 as described above, since the width D1 of the groove 28 of the separate cutter 27 is larger than the width G1 of the inner surface score 36, the two protrusions 27a, The flat surface 29 of 27b contacts the inner surface layer 5, and the protrusions 27a and 27b hardly contact the edge portion H1 of the inner score 36. Therefore, when the cylindrical body 19 is cut, the cut end of the thermoplastic resin film 11 and the separate cutter 27 can be virtually prevented from rubbing (contacting) with each other, and a part of the thermoplastic resin film layer 11 peels off in a thread shape. The occurrence of so-called film hair can be avoided. For this reason, the inconvenience of applying the laminate material to the separate can body is eliminated.

Here, the correspondence between the structure of this embodiment and the structure of the present invention will be described. The thermoplastic resin films 8 and 11 correspond to the film of the present invention, and the outer surface score 35 and the inner surface score 36 correspond to this film. The upper-side blank feed roll 12, the lower-side blank feed roll 13, the upper-side score cutter 14, and the lower-side score cutter 16 correspond to a scheduled dividing groove of the present invention, and correspond to a pair of cutting tools in the present invention. Corresponds to a side edge of the present invention, the separate outer guide 22 corresponds to a first cutting tool of the present invention, the pilot 20 and the separate cutter 27 correspond to a second cutting tool of the present invention, The convex portions 30a and 30b correspond to the receiving portions of the present invention, and the grooves 28 correspond to the concave portions of the present invention.

In the above embodiment, the outer layer 4
May be formed by sequentially laminating a thermoplastic resin film layer, a printing ink layer, and a thermosetting resin layer from the steel plate 3 side. Further, the inner surface layer 5 may be constituted only by the thermoplastic resin film layer. Further, the inner surface layer 5 may be formed by sequentially laminating a thermosetting resin layer and a thermoplastic resin film layer from the steel plate 3 side. Further, a guide member (not shown) as a second cutting tool having a clearance groove formed in the circumferential direction and receiving portions formed on both sides of the clearance groove is brought into contact with the inner surface side of the cylindrical body 19. Even if a cutter (not shown) as a first cutting tool having a convex portion that can enter the escape groove of the guide member is brought into contact with the outer surface side of the cylindrical body 19, the same as in the present invention, The operation and effect of the present invention can be obtained.

[0033]

As described above, according to the first and second aspects of the present invention, the thermoplastic resin film is simultaneously cut in the step of forming the grooves to be cut on both surfaces of the metal plate. In this step, only the groove to be cut is formed in the metal plate, the metal plate is not completely cut, and the relative movement amount between the cutting tool and the metal plate is relatively small. For this reason, in the pressing direction of the cutting tool against the metal plate, the length at which the cut end of the thermoplastic resin film rubs against the cutting tool is relatively short.

Further, the first cutting tool and the second cutting tool are pressed axially away from the dividing grooves on both sides of the cylindrical body by a predetermined distance from the dividing grooves, so that the first cutting tool and the second cutting tool are aligned along the cutting line of the cylindrical body. When a shear load is applied, rubbing (contact) between the second cutting tool and the cut end of the thermoplastic resin film is avoided. Therefore, a cylindrical body manufactured by forming a groove to be cut in a metal plate, and bending the metal plate on which the groove to be cut is formed to overlap the side edges, and joining the side edges. In the process of dividing the thermoplastic resin film along the groove to be cut, the occurrence of so-called film hair, in which a part of the thermoplastic resin film peels off in the form of a thread, can be almost certainly prevented, and the quality of the can body is improved.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a manufacturing process of a separate can body according to the present invention.

FIG. 2 is a perspective view showing a step of forming scores on both surfaces of a metal plate used for manufacturing a separate can body in the present invention.

FIG. 3 is an enlarged sectional view of the metal plate shown in FIG. 2;

FIG. 4 is an enlarged cross-sectional view showing a state in which scores are formed on both surfaces of a metal plate in the step shown in FIG.

FIG. 5 is a partial conceptual view showing a relationship between a cylindrical body and a score cutter in the step shown in FIG.

FIG. 6 is a schematic cross-sectional view showing a state where the cylindrical body is cut in the step shown in FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Metal plate, 1B ... Side edge, 11 ... Thermoplastic resin film, 12 ... Upper side blank feed roll,
13: Lower side blank feed roll, 14: Upper side score cutter, 16: Lower side score cutter, 19 ... Cylindrical body, 20, 21 ... Pilot, 2
2: Separate outer guide, 27: Separate cutter, 27a, 27b: Convex part, 28: Groove, 30
a, 30b: convex portion, 35: outer surface score, 36: inner surface score, 37, 38: can body.

Claims (2)

[Claims] 1. After manufacturing a cylindrical body having a thermoplastic resin film adhered to at least one surface thereof and having a groove to be divided in a circumferential direction thereof, the groove to be divided is formed on the cylindrical body. By applying a shear load along the, in the method of manufacturing a separate can body to produce a plurality of can body by dividing the cylindrical body in the axial direction, a thermoplastic resin film on at least one surface of the metal plate After sticking, by pressing a pair of cutting tools on the same linear area on both surfaces of the metal plate, the thermoplastic resin film is completely cut, and a part of the metal plate is cut. Predetermined grooves are formed at opposing positions on both surfaces of the metal plate. Thereafter, the metal plate is curved and both end edges thereof are overlapped and joined, so that the thermoplastic resin is formed on at least one surface. After manufacturing a cylindrical body on which a resin film is stuck and a groove to be divided is formed at the same position in the axial direction on the inner and outer surfaces, the cylindrical body is formed from the groove to be divided on one surface of the cylindrical body. And pressing the convex portions of the first cutting tool on both sides separated by a predetermined distance in the axial direction of the first cutting tool.
The concave portion formed between the convex portions of the cutting tool and the planned dividing groove are opposed to each other, and the contact positions of the convex portions on both sides in the axial direction of the other surface of the cylindrical body that sandwich the planned dividing groove. Also, at the position near the end portion side of the cylindrical body, pressing the receiving portion of the second cutting tool, respectively, the relief groove formed between the receiving portion of the second cutting tool and the planned dividing groove, By moving the first cutting tool and the second cutting tool relative to each other in a direction in which the convex portion enters the relief groove, along the planned dividing groove with respect to the cylindrical body. A method for manufacturing a separate can body, characterized by applying a shear load. 2. After manufacturing a cylindrical body having a thermoplastic resin film adhered to at least one surface thereof and having a groove to be divided in a circumferential direction thereof, the groove to be divided is formed on the cylindrical body. In a separate can body manufacturing apparatus for manufacturing a plurality of can bodies by dividing the cylindrical body in the axial direction by applying a shear load along, a thermoplastic resin film is adhered to at least one surface. A pair of cuts that are pressed against the same linear area on both sides of the metal plate and that completely cut the thermoplastic resin film, and cut a part of the metal plate to form a groove to be divided A tool, and a metal plate on which the planned dividing groove is formed, and
A can-making machine for manufacturing a cylindrical body by overlapping and joining the both end edges thereof, and convex portions respectively pressed on both sides in the axial direction of the cylindrical body with the divided groove on one surface of the cylindrical body interposed therebetween. And a first cutting tool having a concave portion facing the planned dividing groove when the convex portion is pressed against the cylindrical body, and both sides in the axial direction sandwiching the planned dividing groove on the other surface of the cylindrical body. And a receiving portion that comes into contact with a position closer to the end portion side of the cylindrical body than a contact position of the convex portion, and the first cutting tool is moved in a radial direction of the cylindrical body so as to be divided. After cutting the cylindrical body by applying a shear load along the groove, a second cutting tool having a cut end of the cylindrical body and a relief groove into which the convex portion of the first cutting tool enters. An apparatus for manufacturing a separate can body.