JP2018104094A - Bottle can - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the contents from blowing out in a metal bottle can whose inside cannot be seen. SOLUTION: A shoulder portion 6 whose diameter is reduced from a body portion 5 of a can body 1 centered on a can shaft C toward the upper end side, a neck portion 7 extending from the shoulder portion 6 toward the upper end side, and an upper end portion of the neck portion 7. A cap mounting portion 8 having an opening 4 on the side is provided, and the shoulder portion 6 has a convex curved portion 6a that draws a convex curve bulging toward the outer peripheral side of the can main body 1 in a cross section along the can shaft C, and a neck portion 7. It is provided with a concave curved portion 6c which is connected to the convex curved portion 6a directly or via a straight portion 6b by drawing a concave curve recessed from the lower end to the inner peripheral side, and is in contact with the inner peripheral edge of the opening 4 and intersects the neck portion 7. When the extension line M is rotated to the lower end side while maintaining the state of being in contact with the inner peripheral edge of the opening 4, the inner peripheral surface of the shoulder portion 6 always intersects with the extension line M at one point or is a straight line. The portions 6b are formed so as to overlap each other. [Selection diagram] FIG. 5

Description

  The present invention provides a shoulder having a diameter that decreases from the trunk toward the upper end, a neck that extends further from the shoulder toward the upper end, and a cap that is provided on the upper end of the neck and has an opening at the upper end. The present invention relates to a metal bottle can having an attachment portion.

  As such a bottle can, for example, in Patent Document 1, for example, as a beverage can, it is made of a metal such as aluminum or an aluminum alloy and has a body portion extending along an axis, and the upper end of the body portion. Is provided with a can body having a bottomed cylindrical shape in which an opening is provided and a bottom is provided at the lower end of the body. The opening side portion of the body portion is drawn to have a one-step small diameter. The shoulder portion gradually decreases in diameter toward the upper side in the axial direction and the upper end of the shoulder portion, and extends along the axial line. A cylindrical neck portion is provided, and a base portion having a screw portion is provided in an upper portion of the neck portion.

JP 2009-102042 A

  By the way, in such a bottle can, usually, the portion connected to the trunk portion of the shoulder portion is a convex curve portion that draws a convex curve that swells on the outer peripheral side of the can body in a cross section along the axis (can axis), and the shoulder The portion connected to the neck portion of the portion is a concave curve portion that draws a concave curve that is concave on the inner peripheral side of the can body in the cross section along the can axis, and the shoulder portion gradually decreases in diameter as it goes to the upper end side of the can body. (For example, refer to FIG. 1 of Patent Document 1).

  However, in such bottle cans, the mouth of the can was tilted by trying to drink the contents of liquids such as beverages directly by putting the mouth on the mouthpiece or pouring it into a cup or glass. When the bulge of the convex curve portion is too large, the liquid surface of the contents reaches the boundary between the convex curve portion and the concave curve portion, and the inner surface of the convex curved surface portion is the liquid surface opposite to the base portion. In some cases, a closed space is formed between the inner surface of the convex curve portion and the extended surface of the liquid surface.

  The contents are filled and left in this space until the liquid level reaches the boundary, but at the moment when the liquid level leaves the boundary, the space is opened and air is taken in. As a result, the contents filled in the space may be blown out, and the drinking comfort may be impaired, or the contents may be spilled from a cup or glass. In this regard, if it is a transparent container such as a glass bottle, it is easy to detect in advance that the contents will blow out because it is understood that air has accumulated in the convex curve part in the container. In a container such as a metal bottle can where the inside is not visible, it is difficult to predict the blowout of the beverage.

  The present invention has been made under such a background, and an object of the present invention is to provide a bottle can capable of preventing the contents from being blown out in a metal bottle can whose interior cannot be seen.

  In order to solve the above-described problems and achieve such an object, the present invention comprises a shoulder portion that is reduced in diameter toward the upper end side from the trunk portion of the bottomed cylindrical can body centered on the can shaft, A metal bottle can having a neck portion extending further from the shoulder portion toward the upper end side, and a cap mounting portion provided on the upper end side of the neck portion and having an opening at the upper end, wherein the shoulder portion is In the cross-section along the can axis, a convex curve portion that extends from the upper end of the body portion toward the outer peripheral side of the can body while drawing a convex curve toward the inner periphery of the upper end, and the inner periphery of the can body from the lower end of the neck portion A concave curve portion that faces the outer periphery of the lower end while drawing a concave curve that is recessed on the side, and the upper end of the convex curve portion and the lower end of the concave curve portion are directly connected to each other or on the upper end side of the can body It is connected via a straight part that goes to the inner circumference as it goes, In the cross section, the lower end side is extended toward the inner peripheral side of the can body in contact with the inner peripheral edge of the opening, and the side opposite to the contact with the inner peripheral edge of the opening exceeds the can axis. Assuming an extension line intersecting the inner peripheral surface of the neck, when this extension line is rotated to the lower end side of the can body while maintaining a state in contact with the inner peripheral edge of the opening, The peripheral surface is formed so as to always intersect with the extended line at one point, or to overlap the linear portion.

  When the liquid content such as beverage filled in such a bottle can is poured out from the lower end of the inner peripheral edge of the opening that is inclined by tilting the can body, the liquid level of the content is the lower end of the inner peripheral edge of the opening. In the cross section extending horizontally from the vertical direction along the can axis, the liquid level extends from the lower end of the inner peripheral edge of the opening to the opposite side beyond the can axis while maintaining a horizontal line in contact with the inner peripheral edge of the opening. When the contents are sufficiently filled, it intersects the inner circumferential surface of the opposite neck. That is, the horizontal line overlaps the extension line.

  Here, in the bottle can configured as described above, the inner peripheral surface of the shoulder portion is formed so that it always intersects with the extension line at one point, or the linear portion overlaps, so that the can body is further inclined. Subsequently, the extension line (the horizontal line) is rotated toward the lower end side of the can body while maintaining a state in which the extension line (the horizontal line) is in contact with the inner periphery of the opening relative to the can body, so that the shoulder extends from the inner periphery of the neck. A closed space filled with the contents may be formed between the inner peripheral surface of the can body and the liquid surface before reaching the inner peripheral surface of the body and further reaching the inner peripheral surface of the body. Absent. Therefore, even if it is a container such as a metal bottle can with which the inside cannot be seen, the drinking comfort when drinking with the mouth directly attached is not impaired, and even when pouring a drink into a cup or glass The pouring becomes smooth.

  That is, when the concave curve portion and the convex curve portion of the shoulder are in direct contact with each other, the extension line is placed on the lower end side of the can body by making the tangent line overlap the extension line. As it goes, it goes to the lower end side while intersecting the concave curve portion at one point, intersects the tangent line at the contact point at the contact point between the concave curve portion and the convex curve portion, and then intersects the convex curve portion. Further, even when the concave curve portion and the convex curve portion are bent and connected directly via a bending point, the tangent to the upper end side of the can body of the concave curve portion at the bending point and the convex curve portion at the bending point By passing through the tangent line to the upper end of the can body and intersecting the bending point, the extension line intersects the concave curve portion at one point, and then at the bending point and the inner peripheral surface of the neck portion. It can be made to intersect with the convex curve portion and extend at one point.

  Further, when the concave curve portion and the convex curve portion are connected via a straight line portion, when the straight line portion is formed so as to contact the concave curve portion and the convex curve portion, the straight line portion is defined as the extension line. By making it overlap, this extension line can extend so as to intersect the concave curve part at one point, then overlap with the straight line part, and further extend so as to intersect with the convex curve part at one point, It is possible to prevent the formation of a closed space filled with the contents between the inner peripheral surface of the neck and the liquid surface. In addition, even when the straight line portion is formed so as to contact the concave curve portion and the convex curve portion, or when the straight line portion is bent and connected to the concave curve portion and the convex curve portion via the bending point, By extending the extension line that intersects the straight line part between the extension line that passes through the bending point of the curved part and the concave curve part and the extension line that passes through the bending point of the straight line part and the convex curve part, The extension line may always extend so as to intersect the inner peripheral surface at one point.

  Here, in the cross section along the can axis, when the concave curve portion is drawn from the lower end of the neck portion toward the outer periphery of the lower end of the can body while drawing a concave arc, the center of the concave arc is It is desirable that the distance from the opening in the can axis direction is within a range of 30 mm to 50 mm. When drinking beverages filled in such bottle cans directly from the opening, the can body is often gripped by placing a finger on the concave curve of the shoulder, but the center position is more than 30 mm from the opening. If it is too short, it will be difficult to put your finger on it, and the neck will be shortened and the design will be impaired. On the other hand, if the position of the center is longer than 50 mm from the opening, the capacity of the can body is reduced, and the shoulder portion becomes a so-called shoulder shape, which also impairs the design.

  Further, it is desirable that the neck is formed in a conical surface with the can shaft gradually reducing in diameter toward the upper end side, and a large capacity can be secured if the outer diameter of the neck upper end is the same. . In this case, it is desirable that an inclination angle formed by the neck with respect to a plane perpendicular to the can axis in a cross section along the can axis is in a range of 70 ° to 85 °, from 85 °. If it is larger, the capacity cannot be secured as described above, and if it is smaller than 70 °, if the outer diameter of the shoulder upper end is the same, the neck becomes shorter and it becomes difficult to put a finger on the shoulder and the design is impaired. It is.

  As described above, according to the present invention, when the can body is tilted, a closed space is formed between the liquid surface of the liquid content such as a beverage and the inner surface of the convex curve portion of the shoulder portion. It is possible to prevent the contents left in such a space from being blown out by directly opening the mouth and drinking beverages or when pouring beverages into cups or glasses. As well as ensuring comfort, it is possible to prevent a situation where the beverage is spilled out by smooth pouring.

It is a side view which shows the 1st Embodiment of this invention. It is a top view of embodiment shown in FIG. It is a bottom view of embodiment shown in FIG. It is sectional drawing along the can axis | shaft of embodiment shown in FIG. It is an expanded sectional view of the upper end part of the can main part in FIG. It is a side view which shows the 2nd Embodiment of this invention. It is an expanded sectional view of A part in FIG.

  1 to 5 show a first embodiment of the present invention. As shown in FIGS. 1 and 4, the bottle can of the present embodiment is formed integrally with the bottom portion 2 and the bottom portion 2 so that the can body 1 is integrally formed with the bottom portion 2. , A substantially multi-stage bottomed cylindrical shape centering on a can shaft C provided with an outer peripheral portion 3 extending upward). The outer diameter of the outer peripheral portion 3 is, for example, in the range of 52 mm to 68 mm, and the can height from the lower end of the bottom portion 2 to the upper end of the can body 1 is, for example, in the range of 100 mm to 170 mm.

  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. Further, the outer peripheral portion 3 has a cylindrical body portion 5 centering on the can axis C in order from the bottom portion 2 toward the opening portion 4 on the upper end side of the can body 1, and a shoulder that gradually decreases in diameter toward the upper end side. A neck portion 7 having a conical surface that gradually decreases in diameter from the shoulder portion 6 toward the upper end side, and in this embodiment, a bulging portion 8a and a male screw portion 8b projecting from the upper end of the neck portion 7 to the outer peripheral side. And a cap mounting portion 8 having a curled portion 8c.

  In order to manufacture such a bottle can, first, a cup-shaped material with a shallow depth is manufactured by punching a metal plate such as aluminum or aluminum alloy into a disk shape and performing a drawing process in a cupping press process by a cupping press machine. To do. 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 the dome portion 2a and the annular convex portion 2b are formed on the bottom portion 2. A bottom cylinder (DI can) is formed.

  In this embodiment, the metal plate formed into the cup-shaped material in the cupping press process is an aluminum alloy plate of A3004 or A3104 in JIS H 4000 having a base plate thickness of 0.285 mm to 0.500 mm. In addition, the bottomed cylindrical body formed from the cup-shaped material has a cylindrical portion around the can axis C on the outer peripheral portion, and the outer diameter of the cylindrical portion is outside the body portion 5 of the can body 1. A constant outer diameter substantially equal to the diameter.

  The bottomed cylindrical body formed in this way is cleaned and dried in the first cleaning step, and then the inner and outer surfaces are painted and baked in the coating step. And the bottomed cylindrical body to which the coating has been applied, in the bottle neck forming process by the bottle necker, the lower end side of the upper end side portion of the cylindrical portion is reduced in diameter by a mold, and the shoulder portion 6 and the neck portion 7 are then molded. The upper end side of the neck portion 7 is expanded by a diameter expanding tool to form the bulging portion 8a, and the upper thread side is further threaded from the bulging portion 8a to form the male screw portion 8b. Thereafter, the upper end side of the male screw portion 8b is folded back and curled, and then crushed by throttle processing to form a curled portion 8c to form the cap mounting portion 8, as shown in FIGS. The can body 1 is formed into a can.

  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 from the curled part 8c of the cap attaching part 8 to the male threaded part 8b and the bulging part 8a covering the opening 4. Shipped. In addition, between each said process of the can main body 1, the trimming which cut | disconnects the upper end edge of a bottomed cylindrical body, and the bottom reform which reshapes the cross-sectional shape of the cyclic | annular convex part 2b of a bottom part as needed.

  Here, as shown in FIGS. 4 and 5, the shoulder 6 is in contact with the body 5 at the upper end of the body 5 in the cross section along the can axis C, and the outer periphery of the can body 1. A convex curve portion 6a extending toward the upper end side from the body portion 5 while drawing a convex curve bulging to the side, and in contact with the upper end of the convex curve portion 6a, linearly toward the upper end side of the can body 1, toward the inner peripheral side It is formed by a straight line portion 6b extending toward the upper end and a concave curve portion 6c extending toward the inner periphery side toward the upper end side while drawing a concave curve in contact with the upper end of the straight portion 6b and recessed toward the inner periphery side of the can body 1 Has been.

  And in the cross section along the can axis C, it contacts the inner peripheral edge of the opening 4 and extends to the lower end side toward the inner peripheral side of the can body 1, and contacts the inner peripheral edge of the opening 4 beyond the can axis C. Assuming an extension line M that intersects the inner peripheral surface of the neck 7 opposite to L, the extension line M is rotated to the lower end side of the can body 1 while maintaining a state in contact with the inner peripheral edge of the opening 4. When this is done, the inner peripheral surface of the shoulder portion 6 is formed so as to always intersect the extension line M at one point, or the linear portion 6b overlaps. Here, in the present embodiment, as shown in FIG. 5, the linear portion 6 b is formed so as to overlap the extension line M. Therefore, the inner surface of the convex curve portion 6a of the shoulder portion 6 does not protrude beyond the extension line M in the cross section along the can axis C. That is, the inner surface of the convex curve portion 6a is the inner periphery of the opening 4 And does not protrude beyond the can axis C beyond the straight line that touches the inner surface of the shoulder 6.

  In the present embodiment, in the cross section along the can axis C, the concave curve portion 6c is directed toward the upper end while drawing a concave arc, and the center O1 of the concave arc is from the opening 4 in the can axis C direction. The distance N1 is in the range of 30 mm to 50 mm, and the radius R1 of the concave arc is in the range of 10 mm to 30 mm. Further, the convex curve portion 6a of the shoulder 6 also has a convex arc, and the center O2 of the convex arc has a distance N2 from the opening 4 in the can axis C direction within a range of 55 mm to 75 mm. The radius R2 of the convex arc is in the range of 10 mm to 30 mm.

  Further, the neck portion 7 is formed in a conical surface shape that gradually decreases in diameter toward the upper end side, and an inclination angle formed by the neck portion 7 with respect to the plane P perpendicular to the can axis C in a cross section along the can axis C. θ1 is in the range of 70 ° to 85 °. Furthermore, the inclination angle θ2 formed with respect to the plane P perpendicular to the can axis C in the cross section along the can axis C by the straight portion 6b of the shoulder 6 is in the range of 45 ° to 70 °. Further, the inner diameter (diameter) D of the opening 4 is, for example, in a range of 20 mm to 40 mm.

  In such a bottle can of this embodiment, when the content of liquid such as a beverage filled in the can body 1 is directly taken with a mouth attached to the opening 4, or when poured into a glass or a glass. When the can body 1 starts to be tilted, in the cross section along the can axis C, the liquid level extends from the lower end of the inclined inner peripheral edge of the opening 4 to form a horizontal line. When the can body 1 is further tilted, the upper end of the inner surface of the concave curve portion 6c of the shoulder portion 6 is reached. That is, the horizontal line overlaps the extension line M. When the can body 1 is subsequently tilted, the intersection of the extension line M (horizontal line) and the inner surface of the concave curved portion 6c of the shoulder 6 moves along the concave curved portion 6c, and the lower end of the concave curved portion 6c. That is, the contact point between the concave curve portion 6c and the straight line portion 6b is reached.

  Here, in the present embodiment, as described above, the extension line M (horizontal line) overlaps the straight line portion 6b when reaching the lower end of the concave curve portion 6c, and at the same time, at the lower end of the straight line portion 6b, that is, at the upper end of the convex curve portion 6a. The point of contact between the convex curve portion 6a and the straight line portion 6b is reached. Accordingly, since the convex curve portion 6a is in contact with the straight line portion 6b and does not protrude to the outer peripheral side from the extension line M, the convex curve portion 6a is obtained when the horizontal line overlaps the convex curve portion 6a and the straight line portion 6b. The horizontal line is positioned below the extension line M, which is an extension line to the lower end side of the can body 1.

  For this reason, a space filled with the contents remaining is not formed between the inner surface of the convex curve portion 6a and the surface of the liquid surface extending to the opposite side of the opening 4, so that the can Even if the main body 1 is continuously tilted, the contents will not blow out. Therefore, according to the bottle can having the above-described configuration, when a drink or the like is directly put into the opening 4 and drinks even if the container is invisible such as a metal bottle can such as an aluminum alloy. It is possible to prevent the contents from spilling by smoothing the pouring when pouring into a cup or glass.

  In the present embodiment, between the convex curve portion 6a and the concave curve portion 6c of the shoulder portion 6, the convex curve portion 6a and the concave curve portion 6c at the upper end of the convex curve portion 6a and the lower end of the concave curve portion 6c. However, even if the convex curve portion 6a and the concave curve portion 6c are connected so as to be in direct contact with each other at the upper end of the convex curve portion 6a and the lower end of the concave curve portion 6c. Good. In this case, it suffices if the extension line M extends so as to intersect at the tangent line between the convex curve portion 6a and the concave curve portion 6c at the upper end of the convex curve portion 6a and the lower end of the concave curve portion 6c. The inner peripheral surface of the portion 6 always intersects the extension line M at one point.

  Further, in the present embodiment, in the cross section along the can axis C, the concave curved portion 6c is drawn toward the upper end side while drawing a concave arc, and the center O1 of the concave arc is the opening in the can axis C direction. Since the distance N1 from 4 is in the range of 30 mm to 50 mm, it is possible to improve the gripping ability when gripping the can body 1 and the design of the can body 1 while securing the capacity of the can body 1. it can. That is, if the position of the center O1 of the concave curve portion 6c is shorter than 30 mm from the opening 4, it is difficult to apply the finger when holding the can body 1 with the finger on the concave curve portion 6c. In addition to the deterioration of the properties, the neck 7 is shortened and the design is impaired. On the other hand, if the position of the center O1 is longer than 50 mm from the opening 4, the capacity of the can body 1 is reduced, and the shoulder 6 becomes shoulder-shaped and the design is still impaired.

  Further, in the present embodiment, the neck portion 7 is formed in a conical surface shape that gradually decreases in diameter toward the upper end side of the can body 1, and the neck portion 7 is perpendicular to the can axis C in a cross section along the can axis C. Since the inclination angle θ1 formed with respect to the plane P is in the range of 70 ° to 85 °, it is possible to improve the gripability and design of the can body 1 while ensuring the capacity of the can body 1 as well. it can. That is, when the inclination angle θ1 is larger than 85 °, the capacity of the can body 1 cannot be sufficiently secured, and when the inclination angle θ1 is smaller than 70 °, the upper end of the shoulder portion 6 (concave curve portion 6c). If the outer diameter of the upper end is the same, the neck 7 becomes shorter and it becomes difficult to put a finger on the shoulder 6, and the can body 1 becomes clogged and the design is impaired.

  Next, FIG. 6 and FIG. 7 show a second embodiment of the present invention, and the same reference numerals are assigned to parts common to the first embodiment. In the first embodiment, the straight line 6b overlaps the extension line M on the inner peripheral surface of the shoulder 6, whereas in the second embodiment, the straight line 6b is always at one point with the extension line M. It is characterized by crossing. That is, the straight line portion 6b is not in contact with the convex curve portion 6a and the concave curve portion 6c as its tangent, but is bent at an angle with the tangent line at the upper end of the convex curve portion 6a and the tangent line at the lower end of the concave curve portion 6c. .

  Here, in the cross section along the can axis C, the inner periphery of the opening 4 is contacted by a contact L and extends toward the inner periphery of the can body 1 and extends toward the lower end. The extension line M1 intersecting the inner peripheral surface of the can body 1 on the side opposite to the contact L with the inner peripheral edge at the bending point Q1 between the concave curved portion 6c and the straight portion 6b is a convex curved portion 6a as shown in FIG. Is extended so as to pass through the upper end side of the can body 1 with respect to an extension line M2 that intersects at a bending point Q2 between the straight line part 6b and an extension line M (not shown) that intersects the straight line part 6b. It extends to pass between M1 and M2.

  Therefore, in the present embodiment, the extension lines M, M1, and M2 always extend so as to intersect the inner peripheral surface of the shoulder 6 at one point, and the inner peripheral surface of the shoulder 6 is extended from the extension lines M, M1, and M2. Since the liquid does not protrude to the outer peripheral side, a filled space is formed between the inner surface of the convex curve portion 6a and the surface extending from the liquid surface to the side opposite to the opening 4 to be filled. Even if the can body 1 is continuously tilted, the contents will not blow out.

  Even in the case where the convex curve portion 6a and the concave curve portion 6c are not directly connected via the straight line portion 6b but are bent and connected directly to each other as in the second embodiment, the extension line M Between the tangent to the lower end side of the can body 1 at the lower end of the concave curve portion 6c at the bending point and the tangent to the upper end of the can body 1 at the upper end of the convex curve portion 6a at the bending point. So that the extension line M intersects the concave curve portion 6c at one point, and then intersects at a bending point at one point, and further intersects with the convex curve portion 6a at one point. That is, the inner peripheral surface of the shoulder 6 and the extended surface M can always be crossed at one point.

DESCRIPTION OF SYMBOLS 1 Can main body 2 Bottom part 3 Outer peripheral part 4 Opening part 5 Body part 6 Shoulder part 6a Convex curve part 6b Straight line part 6c Concave curve part 7 Neck part 8 Cap attaching part C Can axis L The extension line M to the inner periphery of the opening part 4, M1 and M2 contact points M, M1 and M2 In the cross section along the can axis C, it contacts the inner peripheral edge of the opening 4 and extends toward the inner peripheral side of the can body 1 and extends to the lower end side, and opens beyond the can axis C. An extension line O1 intersecting the inner peripheral surface of the shoulder 6 opposite to the contact L with the inner peripheral edge of the portion 4 O1 The center of the arc formed by the concave curve portion 6c O2 The center of the arc formed by the convex curve portion 6a N1 Opening 4 The distance in the direction of the can axis C from the center O1 to the center O1 The distance N1 in the direction of the can axis C from the opening 4 to the center O2 The neck 7 forms a plane P perpendicular to the can axis C in the cross section along the can axis C Inclination angle θ2 The straight portion 6b is opposed to a plane P perpendicular to the can axis C in the cross section along the can axis C. Inclination angle to be made D Inner diameter (diameter) of opening 4
Q1 Bending point between concave curve portion 6c and straight line portion 6b Q2 Bending point between convex curve portion 6a and straight line portion 6b

Claims (3)

Provided on the upper end side of the neck part, the shoulder part diameter-reducing from the body part of the bottomed cylindrical can body centering on the can axis toward the upper end side, the neck part extending further from the shoulder part toward the upper end side A metal bottle can having a cap mounting portion provided with an opening at the upper end,
In the cross-section along the can axis, the shoulder portion draws a convex curve that swells from the upper end of the trunk portion toward the outer peripheral side of the can body, and protrudes from the lower end of the neck portion. With a concave curve part toward the outer peripheral side of the lower end while drawing a concave curve recessed on the inner peripheral side of the can body,
The upper end of the convex curve portion and the lower end of the concave curve portion are directly connected or connected via a linear portion toward the inner peripheral side toward the upper end side of the can body,
In the cross section along the can axis, the lower end side extends toward the inner peripheral side of the can body in contact with the inner peripheral edge of the opening, and the contact with the inner peripheral edge of the opening exceeds the can axis Assuming an extension that intersects the inner circumference of the neck on the opposite side,
When this extension line is rotated to the lower end side of the can body while maintaining the state in contact with the inner peripheral edge of the opening,
The bottle can characterized in that the inner peripheral surface of the shoulder portion is formed so as to always intersect the extended line at one point, or to overlap the linear portion. In the cross section along the can axis, the concave curve portion is drawn from the lower end of the neck portion toward the outer periphery of the lower end of the can body while drawing a concave arc,
The bottle can according to claim 1, wherein the center of the concave arc is located within a range of 30 mm to 50 mm from the opening in the can axis direction. The neck is formed in a conical surface centered on the can shaft that gradually decreases in diameter toward the upper end side,
The inclination angle that the neck portion forms with respect to a plane perpendicular to the can axis in a cross section along the can axis is in a range of 70 ° to 85 °. Bottle can.

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