JPWO2018062432A1 - Can body, method for manufacturing can body and manufacturing apparatus for can body - Google Patents

Abstract

An object of the present invention is to make the appearance of a can more excellent. A can body (1) having a can bottom at the lower side in the can axial direction (C), the can body (1) comprising a can lid (3) forming the can bottom; C) a cylindrical body portion (21) extending to the lower end of the body portion (21), and a can body (24) including a curved portion (24) continuous from the lower end of the body portion and curved downward on the inner peripheral side of the body portion 2) formed by winding the end (25) of the curved portion (24) opposite to the body (21) and the peripheral portion (31) of the can lid (3); ) And the can body (2), and the lower end of the above-mentioned tightening part (4) is higher in the can axial direction (C) than the lower end of the bending part (24) Located in

Description

  The present invention relates to a can, a method of manufacturing the can, and an apparatus for manufacturing the can.

In the market, metal cans (drink cans) for beverages filled with beverages such as beer, soft drinks or coffee are widely manufactured, sold, and used by general consumers. Such a beverage can can, for example, be a sheet metal such as aluminum or steel, DI (drawing and
Ironing: It can be obtained by integrally forming the can barrel and the bottom plate (or top plate) by a processing method such as Ironing: drawing or DR (Drawing and Redrawing: drawing). Such beverage cans are called two-piece cans. Such a two-piece can is manufactured by joining a can lid to a beverage-filled can body by winding or the like. For example, as the can body of the two-piece can, one having a neck-in flange formed at the upper end opening of a thin-walled can barrel integrally formed from a bottom plate of a pressure-resistant reinforced shape is used. For this purpose, a can lid with a simple opening called an easy open end smaller in diameter than the can body is used. Then, a two-piece can is formed by winding and tightening the can lid with the simple opening on the neck-in flange of the can body. Further, a beverage can obtained by rolling and joining metal thin plates into a cylindrical shape to form a can body, and joining the bottom plate and the top plate to the can body by winding or the like is called a three-piece can.

  By the way, in recent years, instead of plastic bottles and glass bottles, development of a bottle can having a shape like a bottle and capable of being resealed by a cap or the like has been promoted. Such a bottle can has high light shielding property against ultraviolet light and high sealing property of gas contained in a beverage as compared with a plastic bottle or a glass bottle. That is, by using a bottle can, the preservation property of the beverage which is the content is enhanced. In addition, bottle cans have the advantages of being lighter, less fragile, and easier to recycle, as compared to glass bottles. Therefore, if a bottle can is adopted, it is possible to suppress the cost of the container in all the life cycles such as use and recovery.

  Such a bottle can can be realized by, for example, a two-piece can. For example, the following patent documents 1 to 3 disclose a technique for the structure of the mouth and neck. On the other hand, according to Patent Documents 4 to 7 below, a neck with a small diameter, a shoulder having an inclined surface, and a trunk with a large diameter are integrally formed, and the bottom lid is wound and tightened at the opening at the lower end of the trunk. Thus, there is disclosed a technology for a bottle can which seals contents such as beverages. Such a bottle can can also be realized by a three-piece can. Specifically, Patent Documents 8 and 9 below disclose techniques for a bottle can formed by winding and closing a can body and each of a skirt and a bottom of a mouthpiece lid having an inclination. . Further, Patent Documents 10 and 11 below disclose a technique for turning back the wound portion to the inner peripheral side of the can.

JP 2005-35675 A JP, 2006-273385, A JP, 2013-227083, A JP 2001-114245 A Unexamined-Japanese-Patent No. 2002-263745 Unexamined-Japanese-Patent No. 2004-168346 JP 2008-43965 A JP 2001-170729 A JP 2001-170730 A JP 7-33148 A Japanese Examined Patent Publication No. 5-34064

  While processing of the neck and shoulders is performed from the upper end opening of the two-piece can in the above-mentioned Patent Documents 1 to 3, it is performed from the bottom plate (top plate) of the two-piece can in the above-mentioned Patent Documents 4 to 7 . From the viewpoint of the number of processing steps and technical difficulties in the processing of the neck and shoulders where diameter reduction is required, the processing method shown in the latter is considered to be more advantageous in the manufacture of cans.

  However, in the cans disclosed in Patent Literatures 4 to 7, the winding tightening portion for winding and joining the opening at the lower end of the body portion and the bottom lid is provided on the can bottom side. Then, when the can is placed on a flat surface, the above-mentioned tightening portion is exposed. In this case, since decoration processing such as painting on the outer peripheral surface of the wound portion is difficult, it is difficult to unify the design of the outer appearance of the outer peripheral surface of the wound portion and the outer peripheral surface of the body such as patterns or colors. is there. In addition, since the crimped portion is formed by folding the bottom cover and the trunk portion outward on the outer peripheral side, it has a structure projecting outward from the lower end of the trunk portion, so the appearance of the entire can can not be deteriorated. Has the problem of

  Further, in the cans disclosed in Patent Documents 8 and 9 above, in view of appearance, a winding tightening portion for winding and tightening the can body and the mouthpiece lid is disposed between the can body and the skirt. Although it has become less noticeable, the clasp is still visible from the outside. Furthermore, in the same manner as Patent Documents 4 to 7 above, since the crimped portion obtained by winding and joining the opening at the lower end of the can body and the bottom lid is provided on the can bottom side, when the can is placed There is a problem that the above-mentioned tightening part will be exposed.

  It is also conceivable to make it difficult to visually recognize the wound portion from the outside by folding such a wound portion into the inside of the can by the technique disclosed in Patent Document 10 above. However, in Patent Document 10 above, how to turn back the above-mentioned wound portion (for example, what kind of die for back-folding molding is used and by what process it is necessary to turn back the wound portion) is concrete Not disclosed. Therefore, even if it is attempted to simply form the crimped portion so as to make the crimped portion difficult to visually recognize from the outside, there is a risk that the can body may have a molding failure such as wrinkles or wrinkles during molding.

  Further, according to Patent Document 11, in the case of a can having a double-rolled lid at the open end of the can body, the top portion of the double-wrapped seam band is substantially flush with the folded end edge portion of the can body or It is in a state where it is pushed into the can barrel from the end edge. However, in Patent Document 11 described above, the end of the can barrel is widened by pushing the seam band inward of the can barrel. At this time, the seam band is in contact with the can body on the inner surface of the can. When the seam band and the can body are in contact with each other, the seam band and the can body rub against each other to apply a force to the contact portion, so that the contact portion is likely to be wrinkled.

  Then, this invention is made in view of the said problem, and the place made into the objective of this invention makes the aesthetics of the external appearance of a can body more excellent, and can form the can body which is excellent in the said aesthetic appearance defect. It is to manufacture without.

  In order to solve the above problems, according to one aspect of the present invention, a can body having a can bottom at the lower side in the can axial direction, a can lid forming the can bottom, and a cylinder extending in the can axial direction Provided on the inner circumferential side of the torso body and the can trunk including a curved portion continuous with the lower end of the trunk portion and curved to project downward on the inner circumferential side with respect to the trunk portion; And a winding portion formed by winding and tightening an end opposite to the body portion of the curved portion and a peripheral portion of the can lid, and joining the can lid and the can barrel. The lower end of the winding tightening portion may be located above the lower end of the curved portion in the can axial direction.

  The can body extends from the body to the upper side, and the shoulder decreases in can diameter as it goes upward from the body along the can axis direction, and extends from the shoulder to the upper side than the body The neck and neck may be small in diameter and have an opening at the upper end.

The can diameter D ₁ (mm) of the body portion and the diameter D ₂ (mm) of the winding tightening portion preferably satisfy the following formula (1).
0.75 × D ₁ ≦ D ₂ ≦ 0.88 × D ₁ Formula (1)

  In order to solve the above problems, according to another aspect of the present invention, there is provided a method of manufacturing a can body having a can bottom at the lower side in the can axial direction, the fixing step of fixing a work material; Forming the work material, wherein the work material is continuous from the lower end of the cylindrical body which extends in the can axis direction and which constitutes the side wall part of the can body; The inclined portion whose can diameter decreases as it goes downward along the can axis direction from the body portion, the lid main body forming the can bottom, the lower end portion of the inclined portion, and the peripheral portion of the lid main body And a winding part formed by tightening and joining the lid body and the body part, wherein in the forming step, the lid body and the winding are restrained while restricting the radial movement of the winding part. While pressing the clamping portion upward in the can axial direction, the pressing Forming the inclined portion which is bent along with the body as the curved portion which protrudes downward on the inner peripheral side with respect to the body portion, and the winding is tightened from the lower end of the curved portion which is formed by bending the inclined portion. There is provided a method of manufacturing a can, wherein the lid body and the winding tightening portion are pushed to a position where the lower end of the portion is at the upper side in the can axial direction.

  In the fixing step, the work material is fixed by a die that restrains the outer peripheral surface of the body portion, and in the forming step, a punch disposed on one side of the die in the cylindrical axial direction inside the die The curved portion is formed by pressing it from the can bottom side upward in the can axial direction in a state of being in contact with the lid body and the winding tightening portion, and the punch abuts on the lower surface of the lid body A can lid restraining portion which can be provided, a winding restraining portion having a recess which is provided on an outer peripheral side of the can lid restraining portion and can accommodate the winding tightening portion, and is provided on an outer peripheral side of the winding restraining portion; A curved formed portion having a curved forming surface so as to protrude downward and a curved formed portion having a depth of a curved portion in the forming surface larger than a length in a can axis direction of the winding tightening portion is integrally formed. It is good also as a punch.

The can diameter D ₁ (mm) of the body portion and the diameter D ₂ (mm) of the winding tightening portion may satisfy the following formula (1).

0.75 × D ₁ ≦ D ₂ ≦ 0.88 × D ₁ Formula (1)

  The work material is connected to the upper side from the body part, and a shoulder part whose can diameter decreases as going upward from the body part along the can axis direction, and is connected to the upper side from the shoulder part, from the body part The neck may also be small in diameter and have an opening at the upper end.

  In order to solve the above-mentioned subject, according to another viewpoint of the present invention, it is a manufacturing device of a can which has a can bottom in the lower part in can axial direction, and which fixes a material to be processed; And a punch disposed on one side of the die in the direction of the cylinder axis of the die and forming the workpiece with the die, the workpiece extending in the can axial direction, and the sidewall portion of the can A cylindrical body portion constituting the body, an inclined portion connected from the lower end of the body portion and having a can diameter decreasing downward from the body portion along the can axis direction, and a lid body forming the can bottom And a winding portion formed by winding the lower end portion of the inclined portion and the peripheral portion of the lid main body, and joining the lid main body and the body portion, and the die is the body portion The work material is fixed by restraining the outer peripheral surface of The punch is a can lid restraining portion provided to be able to abut on the lower surface of the lid main body, and a winding restraining portion having a concave portion provided on an outer peripheral side of the can lid restraining portion and capable of accommodating the winding tightened portion. And a molding surface provided on an outer peripheral side of the winding restraint portion and curved so as to protrude downward in the can axial direction, and a depth of a curved portion in the molding surface is the can of the winding clamping portion It is a punch in which the curved shaping | molding part larger than the length of the axial direction was integrally formed, and the said punch is an inner peripheral surface of the said die in the state contact | abutted with respect to the said lid main body and the said winding tightening part. There is provided an apparatus for manufacturing a can, which is provided so as to be movable upward from the can bottom side.

  According to the above-mentioned can, when the above-mentioned can is placed on a flat surface, the crimped portion provided on the inner peripheral side of the curved portion is not visually recognized from the outside. In other words, when the can body is placed on a flat surface, the winding tightening portion is shielded by the curved portion, so that the appearance of the can does not include the configuration of the winding tightening portion. Therefore, it becomes possible to design the design of the external appearance of the can more freely, without being restricted by the presence of the winding part.

  Moreover, according to the manufacturing method and manufacturing apparatus of the said can, when a can is mounted on a flat surface, the crimped part provided in the inner peripheral side of a curved part will not be visually recognized from the outside. In other words, when the can body is placed on a flat surface, the winding tightening portion is shielded by the curved portion, so the appearance of the can does not include the configuration of the winding tightening portion. Furthermore, by restraining the movement of the tightening portion in the radial direction, buckling bending occurs due to the compressive force in the in-plane direction of the inclined portion, and the curved portion is formed. As a result, since the wound portion is unlikely to be pulled in the radial direction, it is possible to suppress the deterioration of the sealing performance due to the peeling of the joined portion and to prevent the molding failure.

  As described above, according to the present invention, it is possible to make the appearance of the can better in appearance and to manufacture the can having excellent appearance without defective molding.

It is a front view which shows an example of a structure of the can 1 which concerns on one Embodiment of this invention. It is the perspective view which looked at the can 1 which concerns on the embodiment from diagonally downward. It is local sectional drawing of the can 1 for demonstrating the structure of the can lid 3 which concerns on the embodiment, the winding fastening part 4, and the curved part 24. FIG. It is a figure for demonstrating an example of a structure of the to-be-processed material 100 immediately after a winding process, and an example of the method of pressing-in. It is sectional drawing (initial stage) which shows an example of a structure of the manufacturing apparatus 10 of the can which concerns on the embodiment. It is sectional drawing (middle stage) which shows an example of a structure of the manufacturing apparatus 10 of the can which concerns on the embodiment. It is sectional drawing (final stage) which shows an example of a structure of the manufacturing apparatus 10 of the can which concerns on the embodiment. It is sectional drawing which shows the structure of the manufacturing apparatus of the can which concerns on the comparative example 1. FIG. It is sectional drawing which shows the structure of the manufacturing apparatus of the can which concerns on the comparative example 2. FIG.

  The present invention will now be described more fully with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. In the present specification and the drawings, components having substantially the same functional configuration will be assigned the same reference numerals and redundant description will be omitted.

  Among the direction axes shown in FIGS. 1A to 6 below, the direction C means the can axis direction of the can 1, and the direction R indicates the radial direction of the can 1. Hereinafter, in the present specification, the can axial direction C and the radial direction R will be described. Furthermore, in the present specification, the direction indicated by the arrow in the can axial direction C shown in FIGS. 1A to 6 (that is, the side of the mouth and neck 23 of the can 1) is upward and the direction opposite to the arrow ( ) Is described as downward. In addition, the can bottom side refers to the can bottom side in the can 1. Moreover, in this specification, the direction shown by the arrow in the radial direction R shown in FIGS. 1A to 6 is described as the outer peripheral direction, and the direction opposite to the arrow is described as the inner peripheral direction. Moreover, about each direction axis | shaft shown to FIG. 4A-FIG. 6, the can axial direction C and the cylindrical axial direction of the die | dye 50 correspond substantially, and the radial direction R and the radial direction of the die | dye 50 correspond substantially. Therefore, in FIGS. 4A to 6, unless it is necessary to distinguish them, the cylindrical axial direction of the die 50 and the can axial direction C are collectively described as the can axial direction C, and the radial direction of the die 50 and the radial direction R And are collectively described as radial direction R.

(Structure of can)
Drawing 1A and Drawing 1B are figures showing an example of composition of can 1 concerning one embodiment of the present invention. FIG. 1A is a front view of the can 1 seen from the front, and FIG. 1B is a perspective view of the can 1 seen obliquely from below. Further, a part of the front view shown in FIG. 1A is expressed as a cutaway view.

  As shown in FIGS. 1A and 1B, the can 1 comprises a can-like body 2 having a bottle-like shape, a can lid 3 and a tightening portion 4. The can 1 which concerns on this embodiment has a form of the bottle can which imitated the shape of what is called a bottle. The raw material which forms this can 1 is thin plate metals, such as aluminum, aluminum alloy, or steel, for example. The material and thickness of the sheet metal forming the can body 2 and the can lid 3 are the required strength, rigidity or strength of the can 1, the type of beverage filled in the can 1, or the manufacturing cost of the can 1 It may be appropriately selected according to the like.

  As shown in FIGS. 1A and 1B, the can body 2 has a body portion 21, a shoulder portion 22, a neck and neck portion 23 and a curved portion 24, and in the can body 2, the body portion 21, the shoulder portion 22, The mouth and neck portion 23 and the bending portion 24 are integrally formed. An example of the method for molding the can barrel 2 will be described later.

  The body portion 21 is a cylindrical portion extending in the can axial direction C, and corresponds to the side wall portion of the can 1. The shape of the body portion 21 is not limited to a simple cylindrical shape as shown in FIGS. 1A and 1B. For example, in order to facilitate gripping of the can 1 and / or to improve the appearance of the can, the can diameter of the body 21 is increased or decreased along the can axial direction C, or the body 21 In a part of the groove, a concave shape, an uneven shape, a groove shape or the like may be provided. Also, processing such as embossing or texture may be performed on the surface of the body portion 21.

  The shoulder 22 is formed continuously from the body 21 to the upper side. The shoulder 22 is hollow and has a structure in which the diameter of the can decreases as going upward from the body portion 21 in the can axial direction C. For example, as shown in FIG. 1A, the shoulder portion 22 is constituted by a curved portion which curves to the outside and the inside of the can barrel 2 and a tapered portion which approaches the can axis as it goes upward along the can axial direction C. May be Of course, the shoulder 22 may be configured only by a tapered shape, or may be configured only by a curved shape. Further, a part of the shoulder portion 22 may be formed in a cylindrical shape parallel to the can axial direction C.

  The mouth and neck 23 is formed continuously with the upper side of the shoulder 22. The mouth and neck portion 23 is a portion corresponding to the spout of the can 1 and has an annular configuration having an opening at the upper end. The upper end may be provided with a curled portion as shown in FIG. 1A. The curled portion may be formed by providing a flange at the upper end of the mouth and neck portion 23 and bending the flange in the outer circumferential direction. The curled portion may be engaged with a cap that closes the opening at the upper end.

  In addition, an external thread (not shown) may be provided on the outer peripheral surface below the upper end of the mouth and neck portion 23. A screw cap can be engaged with such an external thread. Thereby, resealing of the can 1 is attained.

  The curved portion 24 is formed continuously from the lower end of the body portion 21 and is bent in the inner circumferential direction of the can barrel 2 and has a groove shape that protrudes and curves downward in the can axial direction C. That is, the curved portion 24 has an annular groove shape along the outer peripheral edge of the lower end of the can body 2. The detailed configuration of the bending portion 24 will be described later.

  The can lid 3 is a member that forms the can bottom of the can 1. The can lid 3 which concerns on this embodiment consists of the disk-shaped lid main body 30 which occupies a center part, and the peripheral part of the lid main body 30. As shown in FIG. As shown in FIG. 1A, the can lid 3 forms a can bottom by the lid body 30, is joined to the can barrel 2 by the winding tightening unit 4, and seals the opening at the lower end of the can barrel 2. The outer diameter of the can lid 3 may be appropriately set such that the winding tightening portion 4 is positioned on the inner peripheral side relative to the bending portion 24 as described later. The thickness of the can lid 3 can be appropriately set according to the strength, rigidity, manufacturing cost, etc. required of the can 1.

  The tightening portion 4 is formed by winding the can lid 3 and an end portion of the curved portion 24 of the can barrel 2 opposite to the body portion 21. FIG. 2 is a partial cross-sectional view of the can 1 for illustrating the structures of the can lid 3, the winding clamp 4, and the bending portion 24 according to the present embodiment. As shown in FIG. 2, the tightening portion 4 is formed by folding and winding the peripheral portion 31 provided on the outer peripheral side of the lid main body 30 of the can lid 3 and the end 25 of the curved portion 24. . The tightening portion 4 is a joint portion between the can body 2 and the can lid 3, and is formed in an annular shape centered on the can axis along the circumferential direction of the can body 2 and the can lid 3. Further, the tightening portion 4 is provided on the inner peripheral side of the bending portion 24 so that the lower end 4A of the tightening portion 4 is positioned above the lower end 24A of the bending portion 24 in the can axial direction C There is.

  In addition, a sealing material may be appropriately adhered to a gap between the peripheral edge portion 31 and the end portion 25 of the bending portion 24 which constitute the winding tightening portion 4. Such a sealing material may be, for example, a known sealing material such as a resin or a composite material. Such a sealing material is applied or deposited on the interface between the peripheral edge 31 and the end 25, and the peripheral edge 31 and the end 25 are wound, whereby the peripheral edge 31 and the end 25 in the wound portion 4 are obtained. Adheres, the gap between the two is sealed, and the airtightness of the can 1 is more reliably maintained.

  When the can 1 having the above configuration is placed on a flat surface, the lower end 24A of the bending portion 24 contacts the flat surface. That is, the lower end 24A of the curved portion 24 is the bottom of the can 1. At this time, the tightening portion 4 is provided on the inner peripheral side of the bending portion 24 and is provided above the lower end 24A of the bending portion 24 in the can axial direction C. Therefore, when the can 1 is placed on a flat surface, the curved portion 24 on the outer peripheral side shields the wound portion 4 on the inner peripheral side, so that the wound portion 4 can not be visually recognized from the outside. In this case, the appearance of the can 1 when the can 1 is placed on a flat surface does not include the configuration of the winding clamp 4. Therefore, it becomes possible to design the design of the external appearance of the can 1 more freely, without being restricted by the presence of the winding part 4. Therefore, it is possible to make the aesthetics of the external appearance of the can 1 more excellent.

  Moreover, the configuration of the peripheral portion 31 of the can lid 3 constituting the outer side surface of the rolled-up portion 4 is easily changed without being caught by the appearance of the can 1 by making the rolled-up portion 4 invisible from the outside. It becomes possible. For example, the thickness of the can lid 3 can be freely changed. Thus, the thickness of the can lid 3 can be changed according to the strength, rigidity, manufacturing cost, etc. required of the can 1 without considering the influence of the can lid 3 on the appearance of the can 1. .

  In addition, when the conventional can body 1 in which the crimped portion 4 is exposed on the can bottom side falls, the impact of the drop is directly given to the wounded portion 4 and the joint portion of the crimped portion 4 peels off As a result, the sealability of contents such as beverages may be impaired. According to the present embodiment, when the can 1 is dropped, the impact of the drop is directly applied to the crimped portion 4 because the crimped portion 4 enters the body portion 21 side in the can axial direction C. It will be difficult to communicate. Therefore, even if the can 1 is dropped, the impact force applied to the wound portion 4 is reduced, so peeling of the joined portion of the wound portion 4 can be suppressed, and the sealing performance can be less likely to be impaired.

  Note that the depth in the can axis direction C of the curved portion 24 (the length from the lid body 30 to the lower end 24A of the can lid 3) and the width in the radial direction R of the curved portion 24 (the body portion 21 and the tightening portion 4 There is no particular limitation on the distance between Moreover, although the curved part 24 which concerns on this embodiment is a shape which protrudes and curves downward in the can axial direction C, as shown in FIG. 2, the shape of this curved part 24 bends in an inner peripheral direction. It is not particularly limited as long as it has a shape projecting downward as a whole by being driven. For example, even if a shape projecting upward in the can axial direction C may partially occur due to the forming process of the curved portion 24 or the like, the lower end of the body portion 21 to the end 25 of the curved portion 24 The configuration of the curved portion 24 is included in the scope of the present invention as long as it has a shape projecting downward in the can axial direction C as a whole.

  Furthermore, as a result of examination by the present inventor, it is preferable that the distance H between the lower end 4A of the crimped portion 4 and the lower end 24A of the bending portion 24 shown in FIG. If the distance H is 0.5 mm or more, regardless of the shape of the curved portion 24, the winding tightening portion 4 is reliably shielded so that the appearance of the can 1 does not include the configuration of the winding tightening portion 4. It will be possible more surely.

  The configuration of the can 1 according to the present embodiment has been described above.

(Manufacturing method of can)
Next, an example of the manufacturing method of the can 1 which concerns on this embodiment is demonstrated. As described above, the can 1 according to the present embodiment is a so-called two-piece can that is formed by winding the can lid 3 around the open end on the can bottom side of the can barrel 2.

  The manufacturing method of the can 1 which concerns on this embodiment is demonstrated in detail. First, in the method of manufacturing the can 1, the steps up to the step of tightening the can barrel 2 and the can lid 3 will be described.

  In the present embodiment, a blank obtained by punching a thin plate metal is subjected to DI forming to form a cylindrical can body having a top plate and having an open can bottom side. And a shoulder part and a neck are formed by press-forming the top-plate side of a can-barrel. At this time, the mouth and neck become smaller in diameter than the body portion (portion lower than the shoulder portion) of the can barrel by such press molding. By pressing the top plate side, regardless of the material of the thin sheet metal (for example, steel whose formability is relatively inferior to that of aluminum), the number of shoulders and the neck and neck can be reduced with a low number of steps and loss of material. The part can be formed. Then, by trimming the top surface of the top plate, an opening is formed at the upper end of the mouth and neck. Further, the curled portion is formed by curling the peripheral portion of the opening at the upper end of the formed mouth and neck.

  Further, in the present embodiment, the lower end portion of the body portion is formed with an inclined portion which is reduced in diameter toward the inner circumferential direction of the can barrel. Furthermore, a flange portion is formed at the lower end portion of the inclined portion. The ramps and flanges are formed by known necking and flanging. The inclined portion and the flange portion correspond to the above-described curved portion 24 and its end 25 after the winding process. In addition, the connection part of an inclination part, a fuselage | body part, and a flange part may be provided with a radius suitably. The size of the radius is not particularly limited, and is appropriately adjusted in accordance with the diameter reduction ratio (the ratio of the reduction of the can diameter to the can axial direction C) or the like in the inclined portion.

  After the formation of the inclined portion and the flange portion, the peripheral portion of the can lid and the flange portion of the can barrel are wound and tightened by winding. As the winding process, a known winding process such as double winding is used. Thus, the can lid is wound around the open end of the can barrel, and the can bottom of the can 1 is formed by the lid body of the can lid.

  Next, the process which concerns on pressing forming of a winding-fastening part after winding-fastening process is demonstrated, referring FIGS. 3-4C. FIG. 3 is a view for explaining an example of the configuration of the workpiece 100 immediately after the winding process and an example of a method of pressing and forming. As shown in FIG. 3, the material to be processed 100 includes a can barrel 200 and a lid main body 300, and the can barrel 200 and the lid main body 300 are joined by the winding tightening portion 400. The can barrel 200 includes a cylindrical body portion 201, a substantially tapered shoulder portion 202, a substantially annular mouth and neck portion 203, a substantially reverse tapered slope portion 204, and a substantially annular flange portion 205. The material, thickness and the like of the workpiece 100 conform to the material and thickness and the like of the can 1 described above.

  At this time, the crimped portion 400 is positioned on the inner peripheral side of the inclined portion 204 due to the diameter reduction of the inclined portion 204, but is positioned at the bottom of the workpiece 100. In view of this, it is conceivable to press and form the clamping portion 400 (or the lid main body 300) in the direction of the arrow in FIG. 3 while fixing the can barrel 200. As a result, since the crimped portion 400 is pushed toward the body portion 201 side of the can barrel 200, as shown in FIG. 1A, the curved portion 24 becomes the bottom of the can 1 and the can 1 is flat. It is considered that the winding portion 400 can not be visually recognized from the outside when placed on the

  However, as a result of studies by the present inventors, it has been found that the sealing performance and the formability of the wound portion 400 are deteriorated simply by pushing the wound portion 400 or the lid main body 300. Specifically, in the case of simply pressing in the tightening portion 400 or the lid main body 300, the joint portion between the lid main body 300 and the can barrel 200 can be pulled in a direction away from each other. If it does so, the joining location of the crimp part 400 in the peripheral part 301 and the flange part 205 will be torn off. Thereby, the sealability of the winding part 400 may deteriorate.

  Further, referring to Patent Document 6 described above, the winding tightening portion 400 is formed while bending the inclined portion 204 in the inner circumferential direction while fixing the can barrel 200, thereby forming the curved portion 24 that protrudes downward in the can axial direction C. It is also conceivable to arrange the lower end of the bending portion 24 so as to be located above the lower end of the bending portion 24 in the can axial direction C. However, as a result of examinations by the present inventors, the movement in the radial direction R of the crimped portion 400 is not restrained, so that the lid main body 300 and the can barrel 200 are bent when bending the inclined portion 204 in the inner circumferential direction. It has been found that the joints of are pulled away from one another. Therefore, the sealability of the wound portion 400 may be degraded. In addition, a portion where bending in the inner circumferential direction of the inclined portion 204 occurs is displaced at the time of bending. It is difficult to form the shape of the inclined portion 204 into a desired shape, and it is difficult for the winding portion 400 to move upward in the can axial direction C, and as a result, the winding portion 400 is closer to the lower end of the curved portion 24. It has been difficult to arrange them above.

  As described above, it is possible to form the can 1 having a structure in which the crimped portion 4 can not be visually recognized from the appearance without causing molding defects simply by simply pushing the member on the can bottom side of the workpiece 100 into shape. It was difficult.

  Then, the present inventors earnestly studied and arrived at the present invention. In the present invention, in a state in which the workpiece 100 is fixed, the winding tightening portion 400 is pushed upward in the can axial direction C while constraining the movement of the winding tightening portion 400 in the radial direction R. The inclined portion 204 is bent to form a curved portion that protrudes downward in the can axial direction C on the inner peripheral side of the body portion 201. At that time, the lid main body 300 and the tightening portion 400 are pushed to a position where the lower end of the tightening portion 400 is above the lower end of the curved portion formed by bending the inclined portion 204 in the can axial direction C.

  According to this technique, the movement of the winding portion 400 in the radial direction R is restrained, and therefore, when the lid body 300 and the winding portion 400 are pushed in the can axial direction C, the lid body 300 in the winding portion 400 The joint portion with the can barrel 200 is less likely to be pulled in the radial direction R. As a result, the joint between the peripheral edge portion 301 and the flange portion 205 does not peel off, and the sealability of the wound portion 400 can be maintained.

  In addition, when the movement of the tightening portion 400 in the radial direction R is restrained, the bending portion 400 is less likely to be pulled in the radial direction R due to the bending of the inclined portion 204 when the inclined portion 204 is bent. In addition, by restraining the winding portion 400, it is possible to suppress the displacement of the portion where the bending of the inclined portion 204 in the inner circumferential direction occurs. Therefore, the inclined portion 204 can be easily formed into a curved portion having a desired shape, and the lower end of the winding tightening portion 400 can be more reliably positioned above the lower end of the curved portion.

  Hereinafter, an example of a manufacturing device which realizes a method of manufacturing a can according to an embodiment of the present invention and an example of the manufacturing method will be described.

  Drawing 4A-Drawing 4C are sectional views showing an example of composition of manufacturing device 10 of a can concerning this embodiment. FIG. 4A shows an initial stage of the pressing process by the manufacturing apparatus 10, FIG. 4B shows an intermediate stage of the pressing process, and FIG. 4C shows a final stage of the pressing process. The initial stage of the pressing and forming process is the stage before pressing the punch 60 for pressing and forming above the cylindrical axial direction (that is, the can axial direction C) of the die 50, and the intermediate stage is pressing the punch 60. The final stage refers to the stage in which the punch 60 has moved a predetermined distance and the indentation has been completed.

  Referring to FIG. 4A, the manufacturing apparatus 10 according to the present embodiment includes a die 50 and a punch 60.

  The die 50 is, for example, a cylindrical mold that holds the outer periphery of the workpiece 100. The die 50 fixes the workpiece 100 by restraining the outer peripheral surface of the body portion 201 and the shoulder portion 202 of the workpiece 100 installed in the inner space thereof. For example, when the workpiece 100 is installed on the die 50, the workpiece 100 is held by the die 50 by the outer peripheral surface of the body portion 201 of the workpiece 100 being in contact with the inner peripheral surface 50A of the die 50. Ru. Thus, the movement of the body portion 201 in the can axial direction C and the radial direction R is restrained. The shape, structure, and mechanism of the die 50 are not particularly limited, and any configuration may be applied as long as the outer peripheral surface of the body portion 201 abuts and is restrained.

  The punch 60 is a mold for pressing and forming the can bottom side of the workpiece 100 fixed by the die 50. The punch 60 is disposed on one side of the die 50 in the cylindrical axial direction (that is, the can axial direction C) in the internal space of the die 50, and is provided movably in the vertical direction along the circumferential axial direction. The punch 60 bends the inclined portion 204 directly or indirectly in the inner circumferential direction while pushing the lid main body 300 and the tightening portion 400 of the workpiece 100 installed on the die 50 upward in the can axial direction C. , Forming a curved portion. Specifically, as shown in FIG. 4A, the punch 60 according to the present embodiment has a can lid restraint portion 61, a winding clamp restraint portion 62, and a curved shaping portion 63, which together form the punch 60. Do.

  The can lid restraint portion 61 is provided to be able to abut on the lower surface of the lid body 300. When the can lid restraint portion 61 abuts on the lid main body 300 at the time of pressing and forming, it is possible to suppress the displacement in the radial direction R of the lid main body 300 and the out-of-plane deformation of the lid main body 300.

  The can lid restraint portion 61 is provided at a portion that abuts on the lid main body 300 when the workpiece 100 is installed on the upper portion of the punch 60. In the example shown to FIG. 4A, although the can lid restraint part 61 is provided so that contact | abutting may be attained with respect to the whole surface of the lid main body 300, this invention is not limited to this example. For example, using the hollow cylindrical can lid restraint portion 61, the can lid restraint portion 61 may be provided so as to be able to abut on only a part (for example, the outer portion) of the lid main body 300. Further, the outer edge portion of the can lid restraint portion 61 has a shape corresponding to the shape of the boundary portion between the lid main body 300 and the tightening portion 400. For example, in the example shown to FIG. 4A, the outer edge part of the can lid restraint part 61 forms the round shape along the curved surface shape of the said boundary part.

  The winding clamp restraint portion 62 is provided on the outer peripheral side of the can lid restraint portion 61, and forms an annular recess capable of accommodating the winding clamp portion 400. As shown in FIG. 4A, when the pressing and forming process is performed, the winding clamping unit 400 is accommodated in the recess of the winding clamping restraint unit 62, whereby movement of the winding clamping unit 400 in the radial direction R is restrained. The position where the concave portion of the winding restraint portion 62 is provided in the punch 60 is a position facing the winding restraint portion 400, and can be appropriately adjusted according to the processing position in the radial direction R of the winding restraint portion 400 in the workpiece 100 . The preferable range of the diameter of the winding portion 400 will be described later.

  The width of the recess of the winding restraint portion 62 may be appropriately adjusted to be substantially the same as the width in the radial direction R of the winding portion 400 formed by the winding process. Thereby, the restraint of the movement of the tightening portion 400 in the radial direction R can be made more reliable. Although the depth of the recess of the winding restraint portion 62 is not particularly limited, the depth of the recess is from the lid main body 300 to the lower end of the winding restraint 400 in order to reliably accommodate the winding closure 400 in the recess. It is preferable that the length is equal to or greater than the length. As a result, it becomes possible to prevent the occurrence of molding defects of the lid main body 300 in the vicinity of the crimped portion 400 more reliably. Further, the bottom of the recess of the winding restraint portion 62 may not be provided.

  The curved forming portion 63 is a portion provided on the outer peripheral side of the winding restraint portion 62 and on the inner peripheral side of the inner peripheral surface 50A of the die 50. The curved forming portion 63 has a forming surface 63A for forming the curved portion 24 that abuts on the bent inclined portion 204 and protrudes downward in the can axial direction C. That is, the molding surface 63A is an annular groove having a curved shape corresponding to the curved portion 24, and the cross-sectional shape of the molding surface 63A has a curved shape so as to protrude downward.

  When the punch 60 is pushed upward in the can axial direction C in a state in which the punch 60 abuts on the workpiece 100, a bending deformation that causes the upward buckling occurs in a part of the inclined portion 204. The portion where the bending occurs may be a portion that abuts against a portion near the boundary between the curved and molded portion 63 and the winding restraint portion 62. The portion on the outer peripheral side of the bending portion of the inclined portion 204 relatively protrudes downward below the bending portion as the punch 60 is pushed upward. Thereafter, the portion on the outer peripheral side of the inclined portion 204 that protrudes downward abuts against the molding surface 63A, and is deformed along the molding surface 63A to form a curved shape. Thereby, the curved part 24 of the can 1 is formed.

  In addition, as shown to FIG. 4A, depth H of the curved part in the molding surface 63A of the curve shaping | molding part 63 _A(The length in the can axial direction C from the upper surface of the can lid forming portion 61 to the lower end of the forming surface 63A) is the length H of the can axial direction C of the crimped portion 400 of the workpiece 100_BGreater than. Thereby, in the can 1 after shaping | molding, the lower end of the winding fastening part 4 will be located above the lower end 24A of the curved part 24 in the can axial direction C.

  Further, the shape and size of the forming surface 63A is the height of the inclined portion 204 (the length in the can axial direction C from the lower end of the body portion 201 to the lid main body 300, ie, the length of the reduced diameter portion) It may be appropriately designed according to the position, size, etc. of the part 400.

  Next, with reference to FIGS. 4A to 4C, a description will be given of the pressing and forming process using the manufacturing apparatus 10.

  First, in the initial stage of the pressing and forming process shown in FIG. 4A, the body portion 201 is restrained by the die 50 to fix the workpiece 100, and the lid main body 300 is placed on the punch 60. At this time, the lid main body 300 abuts against the can lid restraint portion 61, and the winding tightening portion 400 is accommodated in the winding tightening restraint portion 62. In addition, the curve shaping | molding part 63 does not need to be contact | abutted with the inclination part 204 in the initial stage of a pushing forming process.

  Next, at an intermediate stage of the pressing and forming process shown in FIG. 4B, the punch 60 moves upward along the inner circumferential surface 50A of the die 50 in the can axial direction C, and pushes the lid body 300 and the winding clamp 400 upward. At the same time, bending of the inclined portion 204 is performed. At this time, as shown in FIG. 4B, for example, the contact portion of the inclined portion 204 with the curved forming portion 63 may be bent upward by being pushed in by the curved forming portion 63.

  At an intermediate stage of the pressing and forming process, the movement in the radial direction R of the lid main body 300 and the winding clamp portion 400 is restrained by the can lid restraint portion 61 and the winding clamp restraint portion 62, respectively. Then, an in-plane compressive force is generated in the inclined portion 204 by displacing the winding portion 400 upward while restraining the winding portion 400. Thereby, a buckling may occur at a location where the inclined portion 204 is bent. That is, the bending deformation of the inclined portion 204 can occur not by direct bending of the inclined portion 204 by the punch 60 but by buckling due to compressive force in the in-plane direction with respect to the inclined portion 204 due to the restraint of the winding clamp 400. Then, since a reaction force from the inclined portion 204 is applied to the tightening portion 400, a tensile force in the radial direction R is unlikely to be applied. Therefore, peeling of the joint portion of the rolled portion 400 can be suppressed, and the sealability of the wound portion 400 can be maintained. In addition, the buckling (that is, bending deformation) in the inclined portion 204 may occur not only at the contact portion with the curved shaped portion 63 as shown in FIG. 4B but also at other portions.

  Then, at the final stage of the pressing and forming process shown in FIG. 4C, the inclined portion 204 projects downward and is deformed into a curved shape along the forming surface 63A of the curved and formed portion 63 of the punch 60. Such a curved shape is formed at a portion on the outer peripheral side of the portion where the bending deformation of the inclined portion 204 occurs. The inclined portion 204 after such deformation becomes the curved portion 24 in the can 1. In this final step, the punch 60 is pushed upward from the bottom of the can to a position where the lower end of the tightening portion 400 is higher in the can axial direction C than the lower end of the curved portion 24 formed from the inclined portion 204 . Thereby, in the can 1 obtained after the pressing and forming step, when the can 1 is placed on the flat surface, the winding portion 4 may not be visually recognized from the outside by the curved portion 24.

  The final position of the punch 60 at the final stage of the pressing and forming process is such that the distance in the can axial direction C between the lower end of the pressed clamping portion 4 and the lower end of the formed curved portion 24 is 0.5 mm or more Position is preferable. As described above, when the distance H is 0.5 mm or more, regardless of the shape of the curved portion 24, the winding tightening unit 4 is reliably shielded, and the configuration of the winding tightening unit 4 is not included in the appearance of the can 1. It becomes possible to do so more reliably.

  A can having a configuration in which the winding tightening portion 4 is positioned on the inner peripheral side of the bending portion 24 and the lower end of the winding tightening portion 4 is positioned above the lower end of the bending portion 24 in the can axial direction C Body 1 can be manufactured.

  In addition, the structure of the can lid restraint part 61 which forms the punch 60, the winding clamp restraint part 62, and the curve shaping part 63 is not limited to the structure described in FIG. 4A-FIG. 4C. These configurations can be appropriately designed based on the position, size, shape, and the like of the lid main body 300, the winding clamp portion 400, and the inclined portion 204 of the workpiece 100 to be molded.

Further, as a result of the inventors further studying, the diameter of the winding portion 400 (as shown in FIG. 4A, from the can axis to the position where the can barrel 200 and the lid main body 300 at the root of the winding portion 400 contact It has been found that when the length of (2) is a predetermined size, molding defects due to indentation molding can be suppressed more reliably. Specifically, Kan径of the body portion 201 (the diameter of the outer circumferential surface of the body 201) and D _1, the diameter of the seaming portion 400 when the D _2, it is preferable to satisfy the following formula (1) . If D ₂ 0.750.75 × D _1, it is possible to suppress the occurrence of wrinkles due to the influence of work hardening due to the diameter reduction processing of the inclined portion 204. In addition, the number of processes of diameter reduction processing can be reduced, which is advantageous from the viewpoint of cost. Furthermore, if D ₂ ≦ 0.88 × D ₁ , physical interference between the wound portion 400 and the inclined portion 204 can be suppressed during bending deformation of the inclined portion 204, and the wound portion 400 and the inclined portion 204 do not rub against each other to cause wrinkles, and the forming accuracy of the curved portion 24 can be improved.

0.75 × D ₁ ≦ D ₂ ≦ 0.88 × D ₁ Formula (1)

  In the above, the manufacturing method and manufacturing apparatus 10 of the can 1 which concern on this embodiment were demonstrated.

  Next, examples of the present invention will be described. In order to confirm the effects of the present invention, in this example, the performance of the can 1 manufactured by the manufacturing method and manufacturing apparatus 10 according to the above embodiment was verified. The following examples are merely for verifying the effects of the present invention, and the present invention is not limited to the following examples.

  In the present embodiment, the rolled-up portion 4 of the can 1 obtained after the rolled-up portion 400 of the workpiece 100 is pushed upward from the can bottom side by using the manufacturing method and the manufacturing apparatus 10 according to the above embodiment. The external visibility, the peeling of the joint portion, and the formability of the curved portion 24 are evaluated, and the effectiveness of the present manufacturing method and manufacturing apparatus 10 is shown. In this evaluation, the external visibility of the rolled-up portion 4 was determined by the possibility of visual recognition of the rolled-up portion 4 from the outside of the can 1 when the formed can 1 was placed on a flat surface. . The presence or absence of peeling of the bonded portion of the crimped portion 4 was determined based on whether peeling of the bonded portion of the can lid 3 and the can body 2 of the rolled portion 4 was observed. Further, the formability of the curved portion 24 was determined based on the presence or absence of wrinkles or wrinkles or the like generated in the curved portion 24.

The test conditions and the evaluation results are shown in Table 1 below. As test conditions, the configuration of the punch used, the seaming portion 400 for Kan径_D 1 (mm) and the diameter _D 2 of the seaming portion 400 (mm), and Kan径_{D 1} of the body portion 201 of the workpiece 100 The ratio D ₂ / D _{1 of} diameter D ₂ as well as the height H _S (mm) of the ramp 204 were used. Here, as described above, the height H _S of the inclined portion 204 is the length in the can axial direction C from the lower end of the body portion 201 to the lid main body 300, that is, the length of the reduced diameter portion in the can axial direction C is there. The external visibility and the presence or absence of peeling of the crimped portion and the formability of the curved portion were evaluated for the punch and the can formed from the workpiece satisfying the test conditions. The plate thicknesses of the can barrel 200 and the lid main body 300 that constitute the workpiece 100 used in each of the examples and the comparative examples were each 0.35 mm. The material of the workpiece 100 is T2 of JIS G3303 which is a mild steel plate.

In Examples 1 to 5, pressing was performed on the workpiece 100 using the punch 60 shown in FIG. 4A. The can lid restraint portion 61, the winding tightening restraint portion 62, and the curved shaping portion 63 are lids according to the can diameter D ₁ of the body portion 201, the diameter D ₂ of the winding tightening portion 400, the height H _S of the inclined portion 204, etc. In order to allow the main body 300 to be in contact with the can lid restraint portion 61, the inclined portion 204 can be housed in the shaping surface of the curved shaping portion 63 so that the winding portion 400 can be accommodated in the winding restraint portion 62. It was designed appropriately so as to be deformable along 63A.

  Moreover, in Comparative Examples 1 to 3, pressing was performed on the workpiece 100 using the punch 600 shown in FIG. 5. The punch 600 shown in FIG. 5 comprises only a curved forming portion 601 having a forming surface 601A. That is, when such a punch 600 is used, bending processing can be performed directly on the sloped portion 204 by the curved shaping portion 601. Moreover, in the comparative example 4, pressing-forming was performed with respect to the to-be-processed material 100 using the punch 610 shown in FIG. The punch 610 shown in FIG. 6 consists only of the can lid restraint part 611. That is, when the punch 610 is used, bending deformation may occur in the inclined portion 204 by the lid main body 300 being pushed upward from the can bottom side.

  The evaluation results will be described with reference to Table 1. About the can 1 after shaping | molding which concerns on Examples 1-5, when the can 1 is mounted on a flat surface, the clamp part 4 is not visually recognized from the outside, Furthermore, in the joint part of the clamp part 4, It was confirmed that peeling was not confirmed and sealing performance was maintained. In Example 1, although some creases were observed in the curved portion 24 of the can 1, the creases were visually recognized when the can 1 was placed on a flat surface because it was formed on the can bottom side. It was not done. In Examples 2 to 5, no wrinkles and wrinkles were observed in the curved portion 24 of the can 1, and it was also confirmed that the curved portion 24 formed a shape corresponding to the molding surface 63A.

According to the evaluation results of Examples 3 to 5, it was confirmed that the can 1 having excellent formability can be obtained regardless of the height H _S of the inclined portion 204.

  On the other hand, with regard to the can 1 after forming according to Comparative Examples 1 to 3, in any case, when the can 1 is placed on the flat surface, the winding tightening portion 4 is visually recognized from the outside. Peeling of the joint portion was confirmed, and the shaping of the curved portion 24 was insufficient. This is considered to be because the wound portion 4 is pulled in the radial direction R and the peeling of the bonded portion occurs because the inclined portion 204 is directly bent by the curved formed portion 601. Moreover, since the location where the bending of the inclined part 204 occurs is not stable, and the clamping part 4 is not sufficiently pushed upward from the can bottom side, the forming accuracy of the curved part 24 is low, making the can 1 into a flat surface It is considered that the winding portion 4 was exposed when placed on top.

  Furthermore, in the can 1 which concerns on the comparative example 4, although peeling of the joining part of the crimp part 400 was inconspicuous compared with the can 1 which concerns on Comparative Examples 1-3, it was observed in part. In addition, the crimped portion 400 and the bent inclined portion 204 interfere with each other, and the crimped portion 4 is not pushed in, and is exposed at the time of placing on the flat surface of the can 1. From this, it is considered that the control of the restraint of the winding portion 400 and the control of the bending deformation of the inclined portion 204 is insufficient by pushing the lid main body 300 only by the can lid restraint portion 611.

From this embodiment, in order to manufacture the can 1 in which the tightening portion 4 is not visually recognized from the outside while maintaining the sealing performance of the tightening portion 4, the lid body 300 abuts against the lid main body 300 of the workpiece 100 A can lid restraining portion 61 for restraining, a winding restraining portion 62 for accommodating the winding tightening portion 400 and restraining movement in the radial direction R, and a forming surface 63A for forming the bent portion 204 into a curved shape projecting downward It has been shown that it is effective to push the workpiece 100 upward from the can bottom side of the workpiece 100 using the punch 60 provided with the curved forming portion 63 having the following. Further, with the magnitude of the predetermined range an outer diameter D ₂ of the seaming portion 400 to the outer diameter D ₁ of the body portion 201, it is possible to improve the moldability of the bending portion 24 shown It was done.

  Although the preferred embodiments of the present invention have been described in detail with reference to the accompanying drawings, the present invention is not limited to such examples. It is obvious that those skilled in the art to which the present invention belongs can conceive of various changes or modifications within the scope of the technical idea described in the claims. Of course, it is understood that these also fall within the technical scope of the present invention.

  For example, although the can 1 is in the form of a bottle having a shoulder 22 in the above embodiment, the present invention is not limited to this example. For example, the can may be a substantially cylindrical can. Moreover, in the said embodiment, although the can body 1 presupposed that it is a can manufactured by DI shaping | molding, this invention is not limited to this example. For example, the can may be a can produced by DR molding or may be a so-called three-piece can. Moreover, in the said embodiment, although the can 1 was demonstrated as what is applied to a beverage can, the application object of this invention will not be limited if it is a can which fills and hold | maintains a content inside. That is, if the can bottom of a can is formed by winding by a can lid, the present invention is applicable to any can regardless of the material, use of the can, size and forming method.

Reference Signs List 1 can 2, 200 can body 3 can lid 4, 400 clamp portion 10 manufacturing device 21, 201 body portion 22, 202 shoulder portion 23, 203 mouth and neck portion 24 curved portion 25 end portion of curved portion 24 30, 300 lid Body 31, 301 Peripheral part 50 Die 60 Punch 61 Can lid restraining part 62 Winding restraining part 63 Curved forming part 63A Forming surface 100 Workpiece 204 Sloped part 205 Flange part

Claims (8)

A can having a can bottom at the bottom in the can axial direction, wherein
A can lid forming the can bottom;
A cylindrical body portion extending in the can axis direction, and a can body including a curved portion continuous from the lower end of the body portion and curved to project downward on the inner peripheral side of the body portion;
It is provided on the inner peripheral side of the curved portion, and is formed by winding the end of the curved portion opposite to the body portion and the peripheral portion of the can lid, and the can lid and the can barrel A winding portion for joining the
Equipped with
The lower end of the winding tightening portion is located above the lower end of the curved portion in the can axis direction. The can body is
A shoulder that extends upward from the body portion and decreases in can diameter as it extends upward from the body portion along the can axis direction;
A mouth and neck which extends upward from the shoulder and is smaller in diameter than the body and has an opening at its upper end;
The can according to claim 1, further comprising Can diameter _D 1 (mm) and the seamed portion of the diameter _D 2 of the body portion (mm) satisfies the following formula (1), the can body according to claim 1 or 2.
0.75 × D ₁ ≦ D ₂ ≦ 0.88 × D ₁ Formula (1) A method of manufacturing a can having a can bottom at the lower side in the can axial direction,
A fixing step of fixing the workpiece;
A forming step of forming the fixed work material;
Including
The work material is
A cylindrical body portion extending in the can axis direction and constituting a side wall portion of the can body;
An inclined portion which continues from the lower end of the body portion and whose diameter decreases as it goes downward from the body portion along the can axis direction;
A lid body forming the can bottom;
A winding portion formed by winding and tightening a lower end portion of the inclined portion and a peripheral portion of the lid body, and joining the lid body and the body portion;
Including
In the forming step,
While constraining the movement of the winding part in the radial direction, and pressing the lid main body and the winding part upward in the can axis direction, the inclined part that is bent along with the pressing is included inside the body part It is shaped as a curved portion projecting downward on the circumferential side,
The can body in which the lid main body and the winding tightening portion are pushed to a position where the lower end of the winding tightening portion is higher in the can axial direction than the lower end of the curved portion formed by bending the inclined portion Manufacturing method. In the fixing step,
The workpiece is fixed by a die that restrains the outer peripheral surface of the body portion,
In the forming step,
Inside the die, a punch arranged on one side of the die in the cylindrical axial direction is pushed upward from the can bottom side in the can axial direction while in contact with the lid body and the winding tightening portion Forming the curved portion by
The punch is
A can lid restraint portion provided so as to be able to abut on the lower surface of the lid body;
A winding restraint portion provided on an outer peripheral side of the can lid restraint portion and having a concave portion capable of accommodating the winding clamping portion;
It has a molding surface which is provided on the outer peripheral side of the winding clamp restraint portion and is curved to project downward, and the depth of the curved portion in the molding surface is greater than the length of the winding clamp portion in the can axial direction. A large curved part,
The manufacturing method of the can of Claim 4 which is a punch integrally formed. The can diameter _D 1 of the body portion (mm), and the diameter _D 2 of the seaming portion (mm) satisfies the following formula (1), the production method of the can body according to claim 4 or 5.
0.75 × D ₁ ≦ D ₂ ≦ 0.88 × D ₁ Formula (1) The work material is
A shoulder that extends upward from the body portion and decreases in can diameter as it extends upward from the body portion along the can axis direction;
A mouth and neck which extends upward from the shoulder and is smaller in diameter than the body and has an opening at its upper end;
The manufacturing method of the can of any one of Claims 4-6 which further contain. An apparatus for manufacturing a can having a can bottom at the lower side in the can axial direction,
A die for fixing the workpiece;
A punch disposed on one side of the die in the direction of the cylinder axis inside the die and forming the workpiece with the die;
Equipped with
The work material is
A cylindrical body portion extending in the can axis direction and constituting a side wall portion of the can body;
An inclined portion that continues from the lower end of the body portion and decreases in can diameter as it goes downward from the body portion along the can axis direction;
A lid body forming the can bottom;
A winding portion formed by winding and tightening a lower end portion of the inclined portion and a peripheral portion of the lid body, and joining the lid body and the body portion;
Including
The die fixes the workpiece by restraining an outer peripheral surface of the body portion,
The punch is
A can lid restraint portion provided so as to be able to abut on the lower surface of the lid body;
A winding restraint portion provided on an outer peripheral side of the can lid restraint portion and having a concave portion capable of accommodating the winding clamping portion;
It has a molding surface which is provided on the outer peripheral side of the winding clamp restraint portion and is curved so as to protrude downward in the can axial direction, and the depth of the curved portion in the molding surface is the can axial direction of the winding clamp portion A curved shaped section larger than the length of
Is an integrally formed punch,
The manufacturing apparatus of a can, wherein the punch is provided so as to be movable upward from the can bottom side along the inner peripheral surface of the die in a state of being in contact with the lid body and the winding tightening portion .

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