JP2018154407A - Production method of bottle can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of a bottle can which urges resource-saving, energy-saving, and cost-reducing of a can body.SOLUTION: In a DI press process, redrawing and ironing are given to a cup-like material which is formed from a metal plate with thickness of 0.260 mm to 0.310 mm, so that a cylindrical body 11 with a bottom is formed, where thickness t1 of a thinnest portion 13a of a wall portion 13 that is a thin wall portion is 0.100 mm to 0.130 mm, thickness t2 of a flange portion 14 that is a thick wall portion is 0.160 mm to 0.210 mm, and a step t2-t3 between the flange portion 14 and the thinnest portion 13a of the wall portion 13 is 0.090 mm or less, having a bottom portion 2 and a cylindrical portion 12. In a bottle neck forming process, a shoulder portion, a neck portion, and a cap mounting portion are formed in the flange portion 14 of the cylindrical body 11 with a bottom, so that a bottle can for 310 ml having a can body with can height of 129.0 mm to 135.0 mm is produced.SELECTED DRAWING: Figure 2

Description

  In the present invention, a shoulder portion and a cap attaching portion are formed in a bottle neck forming step on a portion opposite to the bottom portion of the cylindrical portion of the bottomed cylindrical body having a bottom portion and a cylindrical portion formed in the DI press step. The present invention relates to a method for manufacturing a bottle can having a can body.

  As a method for manufacturing such a bottle can, for example, Patent Document 1 discloses a step of forming a metal (aluminum alloy) can body, the can body having a bottom, and the bottom follows the lower portion of the side wall. The side wall of the can body is drawn and squeezed and continues to the wall portion, the wall portion continues to the open upper end, and the wall portion of the can body is formed thicker than the lower portion of the side wall. And a step of forming a frustoconical portion by necking the wall portion a plurality of times, the frustoconical portion being thicker than the wall portion of the can body, Forming a frustoconical portion having a neck portion having a diameter smaller than the diameter of the can body, the neck portion continuing to the cylindrical portion near the upper end opening, and forming a bead on the top portion of the metal can On the cylinder below the bead to secure the closure to the screw. It describes a manufacturing method comprising the steps of forming, and forming an annular bead below the screws.

  Here, in this Patent Document 1, the above-mentioned can body (DI can), which is used in the invention and is subjected to a typical drawing and ironing process, has a metal thickness of about 0.34 mm in the bottom cross-section and about a thin-walled portion. 0.14 mm, and may be about 0.19 mm in the thick section, such a can body having a diameter of about 76.2 mm and a height of about 187 mm to hold 591 ml, or It is also stated that it may be about 216 mm to hold 887 ml.

  Patent Document 1 discloses that the above can body (DI can) for use in the invention has a metal thickness of about 0.25 to 0.38 mm in the bottom cross section and about 0.11 in the thin portion. From about 0.17 mm to about 0.17 mm, and about 0.17 to 0.22 mm at the thick section, such cans having a diameter of about 63.5 to 88.9 mm and a height of about It is also described that it may be 127 to 254 mm.

JP 2006-062755 A

  Here, although the bottle can manufactured by the manufacturing method described in Patent Document 1 has a relatively large capacity as described above, an aluminum alloy for 310 ml generally distributed in Japan. The bottle-made can has a body having a body having a body diameter of about 66 mm and a height of about 132.6 mm, and a bottomed cylindrical body having a bottom portion and a cylindrical portion used for manufacturing such a bottle can. (DI can) has a thickness of the base plate and the bottom of about 0.345 mm, and the thickness of the thin wall on the bottom of the cylindrical part is about 0.135 mm, opposite the bottom of the cylindrical part The thickness of the flange portion, which is a thick portion, is about 0.225 mm, the step between the flange portion and the wall portion is about 0.090 mm, and the mass is about 17.5 g.

  Similarly, the 410ml bottle can distributed in Japan has a body diameter of about 66mm and a can height of about 164mm, and can be used for manufacturing the 410ml bottle can. The bottom cylindrical body has a base plate thickness and a bottom thickness of about 0.400 mm, a wall thickness of about 0.130 mm, a flange thickness of about 0.225 mm, and a step difference between the flange and the wall. It is about 0.095 mm and the mass is about 21.0 g.

  By the way, in recent years, such bottle cans have been required to reduce the weight of the can body in order to save resources of the metal material forming the can body and save energy when manufacturing the material. Even if it can only be made into a bottle, a huge number of bottle cans distributed in the market can achieve significant resource and energy savings or cost reduction of the can body. Here, in order to reduce the weight of such a can body, it is conceivable to reduce the thickness of the bottom portion, the wall portion, and the flange portion by reducing the original plate thickness of the metal plate formed on the can body.

  However, if the original plate thickness of the metal plate is unnecessarily thinned to make the wall and flange portions thinner, the cup-shaped material formed from the metal plate by drawing in the cupping press process is redrawn in the DI press process. When forming a bottomed cylindrical body by ironing, or in the bottleneck molding process on the flanged portion of the bottomed cylindrical body formed in this way, the shoulder (the truncated conical portion), the neck, and the cap mounting portion ( When forming the above-mentioned beads, screws, and annular beads, buckling or deformation may occur in the thinnest wall portion, in particular, the thinnest portion. In particular, if the flange portion is too thin, the cap mounting portion may be cracked in the bottleneck molding process.

  Further, as described above, in the DI pressing process, a wall portion that is a thin portion is formed on the bottom side of the cylindrical portion of the bottomed cylindrical body, and a flange portion that is a thick portion is formed on the side opposite to the bottom portion. In the DI press machine, the flange portion is formed on the outer surface of the punch for performing the ironing process with a plurality of ironing dies at a position corresponding to the flange portion of the bottomed cylindrical body from the wall portion. Is also thick.

  However, if the step between the flange part and the thinnest part of the wall part becomes large due to the thinning, the punching ability from the bottomed cylindrical body is impaired, and a slipping failure occurs, and the DI press machine is stopped and the slipping failure occurs. In addition, the bottomed cylindrical body must be removed from the punch, and the production efficiency and yield of the bottle can may be significantly reduced. In addition, if this level difference is large, stress in the can axis direction due to the molding load is concentrated on the level difference portion in the DI press process or the bottleneck molding process, which may cause buckling or deformation.

  Furthermore, the upper end of the bottomed cylindrical body formed by the DI pressing process and the upper end of the can body in which the shoulder and the neck are formed in the bottleneck forming process on the bottomed cylindrical body are In order to align the height and the can height of the can body, trimming is performed by cutting these upper ends at a predetermined trim margin so as to have a certain height from the bottom.

  However, if a bottomed cylindrical body is formed in the DI press process without balancing the thickness of the flange part and the thickness of the wall part in a metal plate with a reduced original plate thickness, this bottomed cylindrical body and bottleneck forming process In the can body molded in step 1, it is impossible to secure the necessary trim margin at the upper end, and the bottomed cylindrical body and the can body cannot be kept at a certain height due to insufficient trim margin, and must be processed as defective products. You won't get.

  The present invention has been made under such a background. Even if the original plate thickness of the metal plate is reduced in order to reduce the weight of the can body, buckling and punching in the DI press process and the bottleneck forming process are performed. Providing a bottle can manufacturing method that can form a bottomed cylindrical body and can body without incurring any omission defects, trim cost shortage, etc., and promote resource saving, energy saving, and can body cost reduction The purpose is that.

  Here, the inventors of the present invention, as a result of intensive research on the bottle cans for 310 ml and 410 ml, as a result of reducing the original plate thickness of the metal plate in order to reduce the weight of the can body as described above In addition, when redrawing and ironing in the DI press process to the cup-shaped material formed by drawing in the cupping press process from this metal plate, the thinnest part of the wall part which is the thin part on the bottom side of the cylindrical part The thickness is 0.100 mm to 0.130 mm, the thickness of the flange portion on the opposite side of the bottom of the cylindrical portion is 0.160 mm to 0.210 mm, the thinnest of the flange portion and the wall portion Forming a bottomed cylindrical body with a step difference of 0.090 mm or less results in buckling, punch failure in the DI press process and bottleneck molding process, and insufficient trim allowance And without leading to obtaining the knowledge that it is possible to form a can body having a predetermined can height of the bottle can effectively.

  Therefore, the present invention is based on such knowledge, and in order to solve the above-mentioned problems and achieve the above-mentioned object, first, as a method for manufacturing a bottle can for 310 ml, the original plate thickness A cup-shaped material is formed from a metal plate of 0.260 mm to 0.310 mm by drawing in the cupping press process, and the cup-shaped material is redrawn and ironed in the DI press process to have a bottom portion and a cylindrical portion. The thickness of the thinnest part of the wall part which is the thin part on the bottom side of the cylindrical part is 0.100 mm to 0.130 mm, and the thickness of the flange part which is the thick part on the side opposite to the bottom part of the cylindrical part A bottomed cylindrical body having a height of 0.160 mm to 0.210 mm and a step between the flange part and the thinnest part of the wall part of 0.090 mm or less is formed. In the neck forming step, by forming a shoulder portion that is reduced in diameter toward the side opposite to the bottom portion, a neck portion, and a cap attachment portion, a can height from the bottom portion to the upper end of the cap attachment portion is 129. A bottle can having a can body of 0 mm to 135.0 mm is manufactured. The can height is preferably in the range of 131.6 mm to 133.6 mm.

  In addition, based on the same knowledge, the present invention secondly, as a bottle can manufacturing method for manufacturing a 410 ml bottle can, by drawing from a metal plate having a base plate thickness of 0.310 mm to 0.370 mm in a cupping press process. A cup-shaped material is formed, and the cup-shaped material is subjected to redrawing and ironing in a DI pressing process, and has a bottom portion and a cylindrical portion. The thinnest wall portion on the bottom side of the cylindrical portion is the thinnest portion of the wall portion. The thickness of the flange portion is 0.100 mm to 0.130 mm, the thickness of the flange portion on the opposite side of the bottom of the cylindrical portion is 0.160 mm to 0.210 mm, and the flange portion and the wall portion are Form a bottomed cylindrical body with a step difference of 0.090 mm or less from the thin part, and reduce the diameter of the bottomed cylindrical body toward the opposite side of the bottom in the bottleneck molding process. Manufacturing a bottle can having a can body having a can height of 160.0 mm to 166.5 mm from the bottom portion to the upper end of the cap attachment portion by molding a shoulder portion, a neck portion, and a cap attachment portion. Features. The can height is preferably in the range of 163.0 mm to 165.0 mm.

  In the manufacturing method of the first and second bottle cans having such a configuration, the original plate thickness is 0.260 mm to 0.310 mm or 0.310 mm to 0.370 mm, and the thin metal plate, respectively. By forming a bottomed cylindrical body having a thickness in the range based on the above knowledge on the wall portion and the flange portion of the cylindrical portion in the DI press step, buckling or Manufactures bottle cans with can bodies of 129.0 mm to 135.0 mm for 310 ml and 160.0 mm to 166.5 mm for 410 ml without deformation, poor punch removal, or insufficient trim allowance. It becomes possible to do.

  That is, when the thickness of the thinnest part of the wall part is less than 0.100 mm or the thickness of the flange part is less than 0.160 mm, the bottomed cylindrical body or can body is formed in the DI press process or the bottleneck molding process. There is a risk of buckling, deformation and cracking. In addition, when the thickness of the thinnest part of the wall part exceeds 0.130 mm or the thickness of the flange part exceeds 0.210 mm, the bottom is formed from a metal plate having a thin original plate thickness as described above. In the cylindrical body and the can body, the required can height cannot be obtained, resulting in insufficient trim margin.

  Furthermore, if the step difference between the flange part and the thinnest part of the wall part exceeds 0.090 mm, a punch omission occurs when a punch having a concave portion on the outer surface as described above is used in the DI pressing process. There is also a risk that stress due to the molding load concentrates on the step portion in the DI press process or the bottleneck molding process, resulting in buckling or deformation. In the second bottle can manufacturing method, it is desirable that the original plate thickness of the metal plate be in the range of 0.310 mm to 0.365 mm. In addition, considering the buckling and deformation due to the load when attaching the cap to the cap attachment part of the bottle can thus manufactured, the bottomed cylindrical body has a thickness of the flange part of 0.185 mm to 0.210 mm, It is desirable that the step between the flange part and the thinnest part of the wall part be formed to 0.060 mm to 0.090 mm.

  As described above, according to the present invention, in order to reduce the weight of the bottle can, the bottomed cylinder in the DI press process and the bottleneck forming process can be used even if the metal plate formed on the can body is thinned. Can body can be molded at a specified can height without causing buckling and deformation of body and can body, lack of trim allowance, and poor punch removal, greatly reducing resource and energy savings and bottle can cost Reduction can be promoted.

It is a partially broken side view of the can main body of the bottle can manufactured in the 1st Embodiment of the present invention. It is a partial schematic sectional drawing of the bottomed cylindrical body shape | molded by the can main body shown in FIG. It is a partially broken side view of the can main body of the bottle can manufactured in the 2nd Embodiment of this invention. It is a partial schematic sectional drawing of the bottomed cylindrical body shape | molded by the can main body shown in FIG.

  FIGS. 1 and 3 show partially cutaway side views of a can body 1 of a bottle can manufactured in the first and second embodiments of the present invention, respectively. FIGS. It is a fragmentary sectional view showing the outline of bottomed cylindrical body 11 formed in these can bodies 1 in the bottleneck forming step in the second embodiment. The bottle can shown in FIG. 1 has a capacity of 310 ml, and the bottle can shown in FIG. 3 has a capacity of 410 ml. In the can main body 1 and the bottomed cylindrical body 11 in the first and second embodiments shown in FIGS. 1 to 4, the same reference numerals are assigned to common portions.

  As shown in FIGS. 1 and 3, a can body 1 of a bottle can manufactured according to the present embodiment is formed integrally with a bottom portion 2 and the bottom portion 2, and the upper end side from the outer periphery of the bottom portion 2 (FIGS. 1 and 3). It has a substantially multi-stage bottomed cylindrical shape centering on a can shaft C provided with an outer peripheral portion 3 extending upward in FIG. A dome portion 2a having a substantially arc-shaped cross section that is recessed inwardly in the can axis C direction (upper end side of the can body 1) is formed in the bottom portion 2 at the center, and the outer periphery of the dome portion 2a is in the can axis C direction. An annular convex portion 2b that protrudes to the outside (the lower end side of the can body 1) is formed continuously in the circumferential direction around the can axis C.

  In addition, the outer peripheral portion 3 has a cylindrical body portion 5 centering on the can shaft C in order from the bottom portion 2 to the opening portion 4 on the upper end side of the can body 1, and gradually with a constant inclination toward the upper end side. A frustoconical shoulder 6 that has a reduced diameter, a cylindrical neck 7 that extends further from the shoulder 6 toward the upper end, and a bulging portion 8a that projects from the upper end of the neck 7 to the outer peripheral side in this embodiment, A cap attaching portion 8 having a screw portion 8b and a curled portion 8c is formed.

  The can height H from the lower end edge of the bottom part 2 of the can body 1 (the lower end edge of the annular convex part 2b) to the upper end of the outer peripheral part 3 (the upper end edge of the curled part 8c) is a bottle can for 310 ml. In the can body 1 of the embodiment, 129.0 mm to 135.0 mm, preferably 131.6 mm to 133.6 mm, in the can body 1 of the second embodiment which is a bottle can for 410 ml, 160.0 mm to 166.5 mm, Preferably it is 163.0 mm-165.0 mm. Moreover, the diameter of the trunk | drum 5 in the outer peripheral part 3 of the can main body 1 shall be 64.24 mm-68.24 mm with the bottle can of 1st and 2nd embodiment.

In order to manufacture such a bottle can, first, in a cupping press process by a cupping press machine, a cup-shaped material having a shallow depth is manufactured by punching a metal plate into a disk shape having a diameter of 150 mm to 165 mm and performing a drawing process. To do. The metal plate formed into a cup-shaped material in this cupping press process has a base plate thickness of 0.260 mm to 0.310 mm in the first embodiment, and a base plate thickness of 0.310 mm to 0.30 mm in the second embodiment. a aluminum plate or JIS H A3004 or aluminum alloy plate A3104 in 4000 370 mm, 0.2% proof stress after 205 ° C. × 20 minutes baking is used in the range of 235N ^/ mm ² ~265N ^/ mm 2 .

  Next, the cup-shaped material is subjected to redrawing and ironing in a DI press process by a DI press machine and stretched in the direction of the can axis C, whereby a cylindrical portion 12 centering on the can axis C is formed on the outer peripheral portion. At the same time, a bottomed cylindrical body 11 as shown in FIGS. 2 and 4 in which the dome portion 2a and the annular convex portion 2b similar to the can body 1 are formed on the bottom portion 2 is formed. The thickness of the bottomed cylindrical body 11 and the bottom 2 of the can body 1 is substantially equal to the original plate thickness of the metal plate formed into a cup-shaped material in the cupping press process.

  In addition, the cylindrical portion 12 of the bottomed cylindrical body 11 has a constant outer diameter that is substantially equal to the outer diameter of the body portion 5 of the can body 1. Further, a portion on the bottom 2 side of the cylindrical portion 12 is a wall portion 13 which is a thin portion having a reduced thickness (thickness) and an upper end side opposite to the bottom portion 2 (in FIGS. 2 and 4). The upper portion is a flange portion 14 that is a thick portion having a thickness greater than that of the wall portion 13. Here, in order to form the wall portion 13 and the flange portion 14 having different thicknesses in the cylindrical portion 12, as described above, punching is performed in a DI press machine that performs ironing between a plurality of ironing dies. A recess having a depth that takes into account the difference in thickness may be formed at a position corresponding to the flange portion 14 on the outer surface.

  In the bottomed cylindrical body 11 formed in the present embodiment, the wall portion 13 is formed in a plurality of steps (two steps) as shown in FIGS. 2 and 4, that is, the thickness of the bottom portion 2 side is the thickest. Between the first wall portion 13a, which is the thinnest thin portion, and between the first wall portion 13a and the flange portion 14, and is thicker than the first wall portion 13a and thinner than the flange portion 14. A second wall portion 13b is provided. In order to form such a multi-stage wall 13, a recess that is shallower than the recess corresponding to the flange 14 is formed at a position corresponding to the second wall 13 b on the outer surface of the punch of the DI press. The punch recess may be formed in a plurality of stages.

  The first and second wall portions 13a and 13b and the flange portion 14 are substantially constant in thickness, and between the first and second wall portions 13a and 13b and the second wall portion 13b. Between the flange portion 14, the thickness is gradually increased toward the upper end side of the bottomed cylindrical body 11. However, in FIG. 2 and FIG. 4, these thicknesses are drawn with a large ratio with respect to the height and outer diameter of the bottomed cylindrical body 11 for explanation.

  In addition, it is desirable that the length in the direction of the can axis C of the portion where the thickness of the flange portion 14 is constant is preferably in the range of 42 mm to 60 mm in the bottomed cylindrical body 11 of the first and second embodiments. In these embodiments, it is about 52 mm. In the first embodiment, the lengths in the direction of the can axis C of the portions where the thicknesses of the first and second wall portions 13a and 13b are constant are about 26 mm and about 10 mm, respectively. The lengths in the can axis C direction of the portions where the thicknesses of the first and second wall portions 13a and 13b are constant are about 35 mm and about 25 mm, respectively.

  In the bottomed cylindrical body 11 shown in FIGS. 2 and 4, the thickness t1 of the first wall portion 13a that is the thinnest portion of the wall portion 13 of the cylindrical portion 12 is 0.100 mm to 0.130 mm. The thickness t <b> 2 of the flange portion 14 that is the thickest of the cylindrical portions 12 is 0.160 mm to 0.210 mm. Further, the step t2-t1 between the flange portion 14 and the thinnest first wall portion 13a of the wall portion 13 is set to 0.090 mm or less. The thickness t3 of the second wall portion 13b is an intermediate value between the thickness t1 and the thickness t2.

  The bottomed cylindrical body 11 formed in this way is washed and dried in the first washing step after the upper end edge of the cylindrical portion 12 is cut at a predetermined trim margin in the trimming step using a trimmer and the height is aligned. Then, in the painting process, the inner and outer surfaces are painted and baked. Furthermore, in the bottleneck molding process by the bottle necker, the bottomed cylindrical body 11 that has been coated is reduced in diameter in the flange portion 14 of the cylindrical portion 12 to form the shoulder portion 6 and the neck portion 7, and then The diameter of the upper end side of the neck portion 7 is expanded to form a bulging portion 8a, and after a screw portion 8b is formed on the upper end side of the bulging portion 8a, a curled portion 8c is formed on the upper end side of the screw portion 8b. As a result, the cap attaching portion 8 is formed, and the can body 1 of the bottle can as shown in FIG. In this bottleneck molding process, trimming may be performed as necessary.

  After the can body 1 thus molded is cleaned and dried in the second cleaning process, the inspection process is inspected for the presence of pinholes, adhesion of foreign matters on the outer surface, scratches, dirt, printing defects, etc. After being transported and filled with contents such as beverages, a cap (not shown) is attached and sealed and shipped. In addition, during each said shaping | molding process of the can main body 1, or during a shaping | molding process, the bottom reform which reshapes the cross-sectional shape of the cyclic | annular convex part 2b of the bottom part 2 may be performed as needed.

  In the bottle can manufacturing method having such a configuration, in the bottomed cylindrical body 11 formed on the can body 1 in the bottle neck forming step, the first wall portion 13a which is the thinnest portion of the wall portion 13 in the cylindrical portion 12 is formed. The thickness t1 is set to 0.100 mm to 0.130 mm, the thickness t2 of the flange portion 14 is set to 0.160 mm to 0.210 mm, and the step t2-t1 between the flange portion 14 and the first wall portion 13a. 0.090 mm or less, based on the above knowledge, buckling and deformation of the bottomed cylindrical body 11 and the can body 1, lack of trim allowance, punch omission failure as demonstrated in the examples described later. Without being generated, the can body 1 having a predetermined can height H can be formed in each bottle can for 310 ml and 410 ml.

  Therefore, even if the original plate thickness of the metal plate formed on the bottomed cylindrical body 11 is reduced as described above to reduce the weight of the bottle can, a reliable and efficient bottle can can be produced without causing a decrease in yield. Manufacturing can be performed. For this reason, in the present situation where a huge number of bottle cans are distributed in the market, it is possible to save resources and energy, and to promote cost reduction of the bottle cans.

  Here, in the bottomed cylindrical body 11, when the thickness t1 of the first wall portion 13a that is the thinnest portion of the wall portion 13 is less than 0.100 mm, the bottomed cylindrical body 11 is buckled in the DI pressing step. Or deformation may occur. Further, when the thickness t2 of the flange portion 14 of the bottomed cylindrical body 11 is less than 0.160 mm, the can body 1 is also formed in the can body 1 when the shoulder portion 6, the neck portion 7 and the cap attachment portion 8 are formed in the bottle neck forming step. There is a risk of buckling, deformation or cracking. In addition, even if the length in the can axis C direction of the portion where the thickness t2 of the flange portion 14 is constant is less than 42 mm, the can body 1 may be buckled, deformed or cracked in the bottle neck forming process. is there.

  Further, when the thickness t1 of the first wall portion 13a of the wall portion 13 exceeds 0.130 mm or the thickness t2 of the flange portion 14 exceeds 0.210 mm, the metal plate having the thin original plate thickness as described above. In the bottomed cylindrical body 11 formed from the above, it becomes impossible to obtain the required height in the DI press process, resulting in insufficient trim margin, and the can body 1 having a predetermined can height H even if it is sent to the bottle neck forming process. Can no longer be molded. Moreover, when the thickness t2 of the flange part 14 exceeds 0.210 mm, there is a possibility that the molding load in the bottleneck molding process may increase even if the trim margin is not insufficient. Furthermore, if the length in the can axis C direction of the portion where the thickness t2 of the flange portion 14 is constant exceeds 60 mm, the mass may increase.

  Furthermore, when the level difference t2-t1 between the flange portion 14 and the first wall portion 13a which is the thinnest portion of the wall portion 13 exceeds 0.090 mm, a concave portion is provided on the outer surface as described above in the DI pressing process. When a punch is used, a punch omission failure occurs, and the bottomed cylindrical body 11 that has failed to be removed by stopping the DI press must be removed from the punch, resulting in reduced bottle can manufacturing efficiency and yield. End up. Furthermore, if the level difference t2-t1 is too large, the bottomed cylindrical body 11 or the can body 1 may be buckled or deformed due to concentration of stress due to the molding load on the level difference in the DI press process or the bottleneck molding process. There is also. In addition, as will be described in the embodiments described later, in consideration of buckling and deformation due to a load when the cap is attached to the cap attachment portion 8 of the bottle can thus manufactured, the bottomed cylindrical body 11 has a flange portion. 14 has a thickness t2 of 0.185 mm to 0.210 mm, and a step t2-t1 between the flange portion 14 and the first wall portion 13a which is the thinnest portion of the wall portion 13 is formed to 0.060 mm to 0.090 mm. It is desirable.

  Further, in the bottomed cylindrical body 11 of the present embodiment, the wall portion 13 is formed in a plurality of stages having the first and second wall portions 13a and 13b as described above, and these first and second wall portions are formed. Since the thicknesses t1 and t3 gradually increase at 13a and 13b, it is possible to more reliably prevent the punch from coming off and to disperse the stress due to the molding load. However, the wall portion 13 which is the thinnest portion in one step may be formed without providing the first and second multi-step wall portions 13a and 13b.

  Next, examples of the present invention will be given to demonstrate the effects of the present invention. In this example, first, based on the first embodiment shown in FIGS. 1 and 2, the original plate thickness of the metal plate, the thickness t2 of the flange portion 14 of the cylindrical portion 12, the first and second wall portions 13a. Ten bottom cylindrical bodies 11 having various thicknesses t1 and t3 and steps t2 to t1 and t2 to t3 are formed in a DI pressing step by 100 pieces in a DI pressing process. These bottomed cylindrical bodies 11 were molded into the can body 1 in the bottleneck molding step, and the bottleneck moldability (BN moldability) at that time was confirmed. In addition, the diameter (blank diameter) of the metal plate punched into a disk shape was 150 mm. These are shown in Table 1 as Examples 1 to 10 together with the mass of the molded can body 1.

  Moreover, as a comparative example with respect to these Examples 1 to 10, the diameter (blank diameter) of the metal plate punched into a disc shape is 150 mm as in Examples 1 to 10, and the original plate thickness of the metal plate is that of the first embodiment. Although within the range, at least one of the thickness t2 of the flange portion 14 of the cylindrical portion 12, the thickness t1 of the first wall portion 13a, and the step t2-t1 is outside the range of the first embodiment. 100 types of bottomed cylindrical bodies 11 were molded in a DI pressing process to check the DI moldability, and among these bottomed cylindrical bodies 11, those that could be DI press molded were canned in the bottleneck molding process. The body 1 was molded, and the BN moldability at that time was confirmed. These are shown in Table 2 as Comparative Examples 1-6. In addition, since the mass of the shape | molded can main body 1 is substantially the same as the Example which has the same original board thickness, description is abbreviate | omitted. In Examples 1 to 10 and Comparative Examples 1 to 6, the can heights of the cans were averaged 132.6 mm within the range of the first embodiment, and the diameter of the body portion 5 was the same as that of the first embodiment. The average was 66.24 mm within the range of the embodiment.

  Furthermore, also about 2nd Embodiment shown in FIG.3 and FIG.4, based on this 2nd Embodiment, original board thickness of the metal plate, thickness t2 of the flange part 14 of the cylindrical part 12, 1st, Nine types of bottomed cylindrical bodies 11 in which the thicknesses t1 and t3 of the second wall portions 13a and 13b and the steps t2 to t1 and t2 to t3 are variously changed are formed 100 pieces at a time in the DI pressing process, and then DI forming is performed. These bottomed cylindrical bodies 11 were molded into the can body 1 in the bottleneck molding process, and the BN moldability at that time was confirmed. These are shown in Table 3 together with the mass of the molded can body 1 as Examples 21 to 29.

  In addition, as a comparative example for Examples 21 to 29, the thickness of the base plate of the metal plate is within the range of the second embodiment, but the thickness t2 of the flange portion 14 of the cylindrical portion 12 and the first wall portion 13a. The DI moldability is confirmed by molding 100 types of 7 bottomed cylindrical bodies 11 each having at least one of the thickness t1 and the step t2-t1 outside the range of the second embodiment in the DI press step. At the same time, the bottomed cylindrical body 11 that was DI press-moldable was molded into the can body 1 in the bottleneck molding step, and the BN moldability at that time was confirmed. These are shown in Table 4 as Comparative Examples 21-27. Note that the mass of the molded can body 1 is also omitted. In Examples 21 to 29 and Comparative Examples 21 to 27, the can heights of the cans were averaged 164.0 mm within the range of the second embodiment, and the diameter of the body portion 5 was the same as that of the second embodiment. The average was 66.24 mm within the range of the embodiment. Moreover, also in Examples 21-29 and Comparative Examples 21-27, the diameter (blank diameter) of the metal plate punched into a disc shape was 150 mm.

  Here, the evaluation of the DI moldability is shown by the case where all of the 100 bottomed cylindrical bodies 11 that have been molded could be DI press-molded without causing buckling, deformation, or punch failure, and 100 Triangle marks were used when buckling, deformation, or punch failure occurred in up to five of the pieces, and cross marks were given when buckling, deformation, or punch failure occurred in six or more. In addition, the evaluation of BN formability is shown in the case where all of the ones that can be molded according to the predetermined dimensions in the DI press process can be bottleneck molded according to the predetermined dimensions without causing buckling, deformation, cracking, etc. The case where buckling, deformation, cracking or the like had occurred up to 5 pieces was designated as a triangle mark, and the case where buckling, deformation, cracking or the like occurred in 6 pieces or more was designated as a cross mark. Furthermore, when a trim margin shortage occurred in the DI press process, that fact was described in the evaluation, and the bottleneck molding was not performed because the can height H was insufficient.

  Of these, first, in Comparative Examples 1, 2, 4 to 6 and Comparative Examples 21, 23, 24, 26, and 27 in Tables 2 and 4, the level difference t2-t1 was large at 0.100 mm or more. There were many punch defects, and buckling and deformation occurred due to stress concentration due to the molding load on the stepped portion, resulting in a loss of DI moldability. Further, in Comparative Examples 2, 6, and 27 in which the thickness t1 of the first wall portion 13a was less than 0.100 mm, it was also observed that the first wall portion 13a was buckled or deformed in the DI pressing process. Further, in Comparative Examples 3, 22, and 25, since the thickness t2 of the flange portion 14 is larger than 0.210 mm with respect to the original plate thickness, there is a metal plate material redrawn and ironed in the DI press process. The trim margin was insufficient without sufficiently reaching the upper end side of the bottom cylindrical body 11, and the bottleneck could not be formed.

  Also in the bottleneck molding process, in Comparative Examples 1, 2, 21, 23, and 24 in which the thickness t2 of the flange portion 14 is thicker than 0.210 mm, the molding load increases and the BN moldability is impaired. It was. On the other hand, in Comparative Examples 2, 6, and 27 in which the thickness t1 of the first wall portion 13a is less than 0.100 mm, the shoulder portion 6 and the neck portion 7 and the cap attachment portion 8 of the can body 1 are molded when the barrel portion 5 is formed. Buckling and deformation occurred in the first wall portion 13a. Furthermore, in Comparative Examples 1, 2, 4 to 6 and Comparative Examples 21, 23, 24, 26, and 27 in which bottleneck molding was possible without causing a shortage of trim margin, the step t2-t1 was 0.090 mm. Therefore, the BN formability is impaired by buckling or deformation even when stress concentration due to the molding load occurs in the stepped portion.

  In Comparative Examples 1 to 6 and Comparative Examples 21 to 27, in Examples 1 to 10 and Examples 21 to 29, in the DI press process, buckling and deformation, punch omission failure, and trim margin are insufficient. Without occurrence, all 100 bottomed cylindrical bodies 11 could be molded to a predetermined size. Also in the bottleneck molding process, in Examples 1 to 10 and Examples 21 to 26, all 100 bottomed cylindrical bodies 11 molded in the DI press process can be molded into the can body 1 of the bottle can. It was possible. In Examples 9, 10 and 29, 5 or less defective products were generated because the original plate thickness was relatively thin and the thickness t2 of the flange portion 14 was also relatively thin. This is because cracks occurred when the bulging portion 8a was formed by expanding the upper end side of the neck portion 7.

  And in Examples 1-10 which are 310 ml bottle cans, the mass of the can body 1 is 16.1g-13.8g with respect to the conventional 17.5g, and also Examples 21-26 which are 410ml bottle cans. The weight of the can main body 1 was 19.4 g to 16.7 g with respect to 21.0 g of the conventional case, and it was possible to reduce the weight by 1 g or more. This is insignificant for each bottle can, but considering that a huge number of bottle cans are distributed in the market, it means that significant resource and energy savings can be achieved. In addition, mass is the average value of the can main body 1 which could be bottleneck-molded.

  Next, in each of the 10 can bodies 1 formed without buckling or the like in the bottleneck forming step of Examples 1 to 10 and Examples 21 to 29, the top plate portion is attached to the cap attaching portion 8 in the capping step. The outer periphery of the top plate by applying a vertical load (top pressure) in the direction of the can axis C of 850N with a cap made by CSI Japan Co., Ltd. Squeezing to form a stepped portion, and a roll set diameter of 45.3 mm and a thread roller torque of 3.4 N · m are loaded on the inner peripheral side in the radial direction with respect to the can axis C on the top plate side of the peripheral wall by the thread roller. The female screw part is formed so as to follow the screw part 8b, and the roll set diameter is 45.3 mm and the skirt roller torque is 2.6 N · m. The top plate portion of the peripheral wall were capped by tightening around the protuberance 8a bottom giving a load to the radially inner side with respect Kanjiku C hem winding portion opposite (hem tightening) the skirt roller. The capping conditions include capping conditions for a 310 ml aluminum alloy bottle can manufactured from an aluminum alloy plate material having a current original plate thickness of about 0.345 mm, and a current original plate thickness of about 0.400 mm. The capping conditions for a 410 ml aluminum alloy bottle can manufactured from this aluminum alloy sheet were reviewed.

  Here, the thread roller torque and the skirt roller torque are respectively the magnitude of the load applied to the peripheral wall portion when the thread roller forms the female thread portion on the cap molded body, and the skirt roller determines the hem winding portion of the cap molded body. It is a substitute value of the magnitude of the load applied to the skirt winding portion when tightening to the lower end of the bulging portion 8a, that is, the torque value of the driving arm for pressing each roller against the radially inner side with respect to the can shaft C. Show. The roll set diameter is the distance between the edges on the radially inner peripheral sides of the rollers facing each other when these rollers are at the initial set position farthest from the can axis C (opposite with the can axis C as the center). The diameter of the circle inscribed in the inner peripheral edge of the roller), and the tip load of each roller at the time of forming the female thread portion and at the bottom of the skirt can be calculated from the roll set diameter, the thread roller torque, and the skirt roller torque.

  As for capping performance, the reseal torque is measured when the cap formed from the cap molded body in the capping step and attached to the cap attaching portion 8 is once opened and then re-sealed by screwing into the cap attaching portion 8 again. did. When the cap mounting portion 8 is buckled or deformed due to the molding load in the capping process, the frictional resistance between the screw portion 8b of the can body 1 and the female screw portion of the cap increases, and the reseal torque also increases. When the reseal torque is 20 N · cm or more, a sense of resistance at the time of resealing can be understood by a human hand, but in Examples 1 to 10 and Examples 21 to 29, the reseal torque becomes 20 N · cm or more. There wasn't.

  Therefore, next, 10 can bodies 1 manufactured in the same manner as in Examples 1 to 10 and Examples 21 to 29 are provided on the cap mounting portion 8 in the capping step and have a top plate portion and a peripheral wall portion with a diameter of 38 mm. Cover the bottom cylindrical cap molded body and draw the top plate outer periphery by applying a vertical load (top pressure) in the direction of the can axis C of 1000 N with a cap made by CSI Japan Co., Ltd., and roll set diameter Form the internal thread with 45.3 mm and thread roller torque of 3.8 N · m, and the inner diameter in the radial direction with respect to the can axis C at the hem winding with the same roll set diameter of 45.3 mm and skirt roller torque of 3.0 N · m Capping the bottom of the bulging portion 8a by applying a load to the bulging portion 8a and capping the cap, and once opening the cap thus attached It was measured resealing torque when resealing screwed to the cap attachment portion 8 again. The capping conditions include capping conditions for a 310 ml aluminum alloy bottle can manufactured from an aluminum alloy plate material having a current base plate thickness of about 0.345 mm, and aluminum having a current base plate thickness of about 0.400 mm. It is close to the capping conditions for a 410 ml aluminum alloy bottle can manufactured from an alloy sheet.

  As a result, the thickness t2 of the flange portion 14 is 0.185 mm to 0.210 mm, and the step t2-t1 between the flange portion 14 and the first wall portion 13a, which is the thinnest portion of the wall portion 13, is 0.060 mm to 0.03 mm. In the can bodies 1 of Examples 1 to 6 and Examples 21 to 27 molded from the bottomed cylindrical body 11 of 090 mm, there was no reseal torque of 20 N · cm or more, whereas the thickness of the flange portion 14 Examples 7 to 10 and Examples 28 to 29 formed from the bottomed cylindrical body 11 in which the thickness t2 is less than 0.185 mm, or the step t2-t1 between the flange part 14 and the first wall part 13a is less than 0.060 mm. In the can body 1, one to 10 resealing torques of 20 N · cm or more were observed. Therefore, the thickness t2 of the flange portion 14 is 0.185 mm to 0.210 mm, and the step t2-t1 between the flange portion 14 and the first wall portion 13a that is the thinnest portion of the wall portion 13 is 0.060 mm to 0.090 mm. It can be seen that it is desirable to form the can body 1 from the bottomed cylindrical body 11.

DESCRIPTION OF SYMBOLS 1 Can main body 2 Bottom part 2a Dome part 2b Annular convex part 3 Outer peripheral part 4 Opening part 5 Trunk part 6 Shoulder part 7 Neck part 8 Cap attaching part 8a Expansion part 8b Screw part 8c Curl part 11 Bottomed cylindrical body 12 Cylindrical part 13 Wall Part 13a First wall part 13b Second wall part 14 Flange part C Can shaft H Can height t1 Thickness of first wall part 13a t2 Thickness of flange part t3 Thickness of second wall part 13b

Claims (3)

A cup-shaped material is formed by drawing in a cupping press process from a metal plate having a thickness of 0.260 mm to 0.310 mm.
The cup-shaped material is subjected to redrawing and ironing in the DI pressing process, and has a bottom portion and a cylindrical portion. The thickness of the thinnest portion of the wall portion, which is a thin portion on the bottom side of the cylindrical portion, is 0. 100 mm to 0.130 mm, the thickness of the flange portion, which is the thick portion opposite to the bottom portion of the cylindrical portion, is 0.160 mm to 0.210 mm, and there is a step between the flange portion and the thinnest portion of the wall portion. Forming a bottomed cylindrical body of 0.090 mm or less,
In the bottleneck molding step, the cap portion is attached to the flange portion of the bottomed cylindrical body from the bottom portion by molding a shoulder portion, a neck portion, and a cap attachment portion that are reduced in diameter toward the opposite side of the bottom portion. The bottle can which has a can main body whose can height to the upper end of a part is 129.0 mm-135.0 mm is manufactured, The manufacturing method of the bottle can characterized by the above-mentioned. A cup-shaped material is formed by drawing in a cupping press process from a metal plate having a thickness of 0.310 mm to 0.370 mm.
The cup-shaped material is subjected to redrawing and ironing in the DI pressing process, and has a bottom portion and a cylindrical portion. The thickness of the thinnest portion of the wall portion, which is a thin portion on the bottom side of the cylindrical portion, is 0. 100 mm to 0.130 mm, the thickness of the flange portion on the opposite side of the bottom of the cylindrical portion is 0.160 mm to 0.210 mm, and the step between the flange portion and the thinnest wall portion is 0 Form a bottomed cylindrical body of .090 mm or less,
In the bottleneck molding step, the cap portion is attached to the flange portion of the bottomed cylindrical body from the bottom portion by molding a shoulder portion, a neck portion, and a cap attachment portion that are reduced in diameter toward the opposite side of the bottom portion. A bottle can having a can height of 160.0 mm to 166.5 mm up to the upper end of the portion is manufactured.   The bottomed cylindrical body having a thickness of the flange portion of 0.185 mm to 0.210 mm and a step difference between the flange portion and the thinnest portion of the wall portion of 0.060 mm to 0.090 mm is formed. The manufacturing method of the bottle can of Claim 1 or Claim 2.

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