Can

Abstract

To provide a bottomed cylindrical can used for a two piece can, a bottle can or the like to be filled with a content such as a beverage.SOLUTION: A can having a bottomed cylindrical shape comprises a can bottom and a cylindrical can barrel extending upward from the upper end of an expanded diameter portion of the can bottom. The can barrel comprises a curved surface 300 disposed on a virtual cylindrical surface, and a first groove part 310 connected to the curved surface part 300 and recessed toward a can center axis. The first groove 310 comprises a first side face 311A and a second side face 311B in which a distance therebetween gradually decreases as the groove becomes deeper, and a convex part 312 disposed between the deepest portion of the first side face 311A and the deepest portion of the second side face 311B, extending in the longitudinal direction of the first groove 310 together with the first side face 311A and the second side face 311B, and protruding toward the virtual cylindrical surface.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a bottomed cylindrical can body used for a two-piece can, a bottle can, etc. filled with contents such as beverages.

Background Art

[0002] A two-piece can is known, which includes a can body filled and sealed with contents such as beverages, and a disc-shaped can lid wound around a flange portion at an opening end of the can body. The can body includes a can body portion (wall) and a can bottom portion (bottom), and is formed in a bottomed cylindrical shape. The can body is a DI can, and "DI" is an abbreviation for Drawing & Ironing. Also, as a can body, a bottle can with a cap screwed onto an opening end is well known. The can body is filled with contents such as beverages inside, and in the case of a two-piece can, the can lid is wound around the flange portion, and in the case of a bottle can, the cap is screwed onto the opening end, so that the can body is sealed and the can product is completed.

[0003] Conventionally, those having a groove portion provided on the cylindrical surface of the can body portion are known (Patent Documents 1 to 3). The can container disclosed in Patent Document 1 has a concave bead provided on the can body, and is configured such that the can body is easily deformed, such as being folded with the concave bead as a boundary by pushing a portion of the can body where the concave bead is not formed. The can disclosed in Patent Document 2 has a plurality of depressions (beads) inclined with respect to the axial direction of the body portion and extending on the outer surface of the body portion arranged in parallel, and the outer surface of the body portion is configured in an uneven shape to enhance the strength of the can body. The metal can disclosed in Patent Document 3 has a transverse groove extending in the circumferential direction of the can body portion separated from a longitudinal groove extending parallel to the axial direction of the can body portion, and further, a reinforcing groove connecting a plurality of transverse grooves to each other is further formed on the outer peripheral surface of the can body portion, preventing the influence of buckling generated in the transverse groove from being propagated to the longitudinal groove, and being strongly configured against longitudinal loading.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

Patent Document 3

Summary of the Invention

Problems to be Solved by the Invention

[0005] By the way, when the can body has a groove, the strength of the can body tends to be weakened regardless of the thickness of the can body. And when the thickness of the can body is reduced, the reduction in strength becomes more remarkable. Therefore, it is desirable to increase the strength of the can body provided with the groove in the can body.

[0006] An object of the present invention is to provide a can body to solve the above problems.

Means for Solving the Problems

[0007] The present invention is a can body formed in a bottomed cylindrical shape, comprising a can bottom portion and a cylindrical can body portion extending upward from the upper end of the can bottom portion, wherein the can body portion includes a curved surface portion disposed on a virtual cylindrical surface, and a first groove portion connected to the curved surface portion and recessed toward the can central axis from the virtual cylindrical surface, the first groove portion including first side surface portions and second side surface portions whose intervals gradually decrease as the depth increases, and a first reinforcing portion disposed between the deepest portion of the first side surface portion and the deepest portion of the second side surface portion and extending in the longitudinal direction of the first groove portion together with the first side surface portions and the second side surface portions. The first reinforcing portion is characterized in that it is any one of a convex portion protruding toward the virtual cylindrical surface, a concave portion recessed toward the can central axis, and an uneven portion formed by arranging the convex portion and the concave portion side by side in the groove width direction orthogonal to the longitudinal direction of the first groove portion.

[0008] By providing the first groove portion with any one of a convex portion, a concave portion, and an uneven portion, the rigidity of the can body portion can be increased. The uneven portion is not limited to the combination of the convex portion and the concave portion, and may be a combination of the convex portions or a combination of the concave portions.

[0009] The can body of the present invention preferably has the convex portion disposed between the first side surface portion and the second side surface portion, the width of the first groove portion being 2.00 mm or more and 4.00 mm or less, the maximum depth of the first groove portion being 0.10 mm or more and 0.30 mm or less, and the height of the convex portion from the deepest portion of the first groove portion being 0.05 mm or more.

[0010] By providing a protruding convex portion with a height of 0.05 mm or more and 0.15 mm or less in a first groove portion having a width of 2.00 mm or more and 4.00 mm or less and a maximum depth of 0.10 mm or more and 0.30 mm or less, the rigidity of the can body portion can be increased. If the width of the first groove portion is less than 2.00 mm, it becomes impossible to process, and if the width of the first groove portion is greater than 4.00 mm, the visibility of the groove portion deteriorates, which is not preferable. Also, if the maximum depth of the first groove portion is less than 0.10 mm, the visibility of the groove portion deteriorates, and if it is deeper than 0.30 mm, it becomes impossible to process, which is not preferable. Further, if the height of the convex portion is less than 0.05 mm, the effect of the invention becomes weak. In the can body of the present invention, the cross-section of the convex portion orthogonal to the longitudinal direction of the first groove portion is formed, for example, in an arc shape of a semi-circle.

[0011] The can body of the present invention preferably has the concave portion disposed between the first side surface portion and the second side surface portion, the width of the first groove portion being 2.00 mm or more and 4.00 mm or less, the depth of the ends at the deep positions of the first side surface portion and the second side surface portion being 0.10 mm or more and 0.30 mm or less, and the depth of the deepest portion of the concave portion being 0.15 mm or more and 0.45 mm or less.

[0012] By providing a concave portion with a depth of 0.15 mm or more and 0.45 mm or less in a first groove portion having a width of 2.00 mm or more and 4.00 mm or less and the depth of the ends at the deep positions of the first side surface portion and the second side surface portion being 0.10 mm or more and 0.30 mm or less, the rigidity of the can body portion can be increased. If the width of the first groove is less than 2.00 mm, it cannot be processed. If the width of the first groove is greater than 4.00 mm, the visibility of the groove becomes poor, which is not preferable. Also, if the depth of the ends at the deep positions of the first side surface portion and the second side surface portion is less than 0.10 mm, the visibility of the groove becomes poor. If it is deeper than 0.30 mm, it cannot be processed, which is not preferable. Furthermore, if the maximum depth of the concave portion is less than 0.15 mm, the effect of the invention becomes weak. If it is deeper than 0.45 mm, it cannot be processed, which is not preferable. In the can body of the present invention, the cross-section of the concave portion orthogonal to the longitudinal direction of the first groove is formed, for example, in an arc shape of a semi-circle.

[0013] The can body of the present invention further includes a second groove that is connected to the curved surface portion and recessed toward the can central axis from the virtual cylindrical surface. The second groove includes an arc-shaped portion that extends in an arc shape from one end to the other end. The other end of the arc-shaped portion is displaced in the circumferential direction or in the direction opposite to the circumferential direction from the one end, and is provided at a position displaced upward or downward. Further, the first groove is provided adjacent to the arc-shaped portion or beside the arc-shaped portion with the curved surface portion interposed therebetween. Also, the can body of the present invention further includes an annular second groove that is connected to the curved surface portion and recessed toward the can central axis from the virtual cylindrical surface. The second groove has a lower end portion formed closer to the can bottom, an upper end portion formed at a position higher than the lower end portion, a first intermediate end portion that constitutes the portion farthest from the lower end portion and the upper end portion in the circumferential direction, and a second intermediate end portion that constitutes the portion farthest from the lower end portion and the upper end portion in the direction opposite to the circumferential direction. Between each of the lower end portion and the upper end portion and each of the first intermediate end portion and the second intermediate end portion, it is formed as an arc-shaped portion that extends in an arc shape. The first groove is provided outside the second groove, adjacent to the arc-shaped portion or beside the arc-shaped portion with the curved surface portion interposed therebetween. For example, when a load is applied to the can body from above or from below, in the annular second groove portion, the arcuate portion may have a lower strength compared to the upper portion, the lower portion, the first intermediate end portion, and the second intermediate end portion. However, since the first groove portion provided with the first reinforcing portion is formed adjacent to these arcuate portions or in proximity thereto via the curved surface portion, the arcuate portion of the second groove portion and the periphery thereof are reinforced. Without providing the first groove portion, it is impossible to prevent deformation of the arcuate portion of the second groove portion and the surrounding portions.

[0014] The can body of the present invention preferably has, in the arcuate portion of the second groove portion, a first side surface portion and a second side surface portion whose intervals gradually decrease as the depth increases, and is disposed between the first side surface portion and the second side surface portion of the second groove portion and extends in the longitudinal direction of the second groove portion together with the first side surface portion and the second side surface portion of the second groove portion. The second reinforcing portion includes a convex portion protruding toward the virtual cylindrical surface, a concave portion recessed toward the can central axis, and any one of uneven portions formed by arranging the convex portion and the concave portion of the second reinforcing portion in the groove width direction orthogonal to the longitudinal direction of the second groove portion. By providing the second groove portion with the second reinforcing portion, the rigidity of the can body can be further enhanced.

Effects of the Invention

[0015] According to the present invention, by providing the first groove portion with the first reinforcing portion, the strength of the can body can be increased.

Brief Description of the Drawings

[0016]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Figure 12

Figure 13

Figure 14

Figure 15

Figure 16

Figure 17

Figure 18

Figure 19

Figure 20

Figure 21

Figure 22

Embodiments for Carrying Out the Invention

[0017] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. The can body 10 according to the embodiment of the present invention shown in FIG. 1 is filled with contents such as a beverage, and then sealed by wrapping and attaching a can lid (not shown) to a flange portion 60 at the open end. As shown in FIG. 2, the can body 10 is formed in a bottomed tubular shape and includes a can bottom 20 having a ring-shaped ground contact portion 21 and an expanded diameter portion 22 that gradually expands in diameter from the outer periphery of the ground contact portion 21 upward, a cylindrical can body 30 that extends upward from the upper end of the expanded diameter portion 22 of the can bottom 20, a reduced diameter portion 40 that gradually reduces in diameter from the upper end of the can body 30 upward, a neck portion 50 that extends upward from the upper end of the reduced diameter portion 40 and has a constant outer diameter, and a flange portion 60 that expands outward from the upper end of the neck portion 50.

[0018] Furthermore, the can body 30 of the can body 10 includes a curved portion 300 arranged on an imaginary cylindrical surface, and a linear first groove portion 310 and an annular second groove portion 320 that are connected to the curved portion 300 and are recessed toward the can center axis C from the imaginary cylindrical surface.

[0019] The first grooves 310 are recesses extending linearly from one end 38A to the other end 38B, and are provided around the six second grooves 320 on the front side of the can body 30. The first grooves 310 are arranged with one end 38A offset from the second grooves 320 in the circumferential direction or in the opposite direction to the circumferential direction, and the distance between the first grooves 310 increases toward the other end 38B, and the first grooves 310 extend radially from the second grooves 320. When the can body 10 is viewed in plan, the circumferential direction is, for example, clockwise or counterclockwise about the can center axis C, and the following description is based on the clockwise direction. Second groove portion 320 is a recess formed between annular edge 303A of curved portion 300 and annular edge 303B disposed therearound, and has a vertically elongated ring shape when viewed from the front of can body 10. In the illustrated example, it is elliptical, but the shape of the ring is not limited to an ellipse and may be rectangular or another polygonal shape. On the front side of the can body 30, with the second groove portion 320 disposed therebetween, the first groove portions 310 extend radially. Such a configuration in which a plurality of first groove portions 310 extend radially from the second groove portion 320 is not shown in the drawings, but may also be formed on the back side of the can body 30.

[0020] Next, the specific structure of the first groove portion 310 will be described. As shown in FIG. 3, the first groove portion 310 includes a groove side surface portion 311 extending from an annular opening edge 301 formed in the curved surface portion 300 toward the can central axis C, and a convex portion 312 protruding from a deep position of the groove side surface portion 311 toward the virtual cylindrical surface as a first reinforcing portion. The groove side surface portion 311 includes a first side surface portion 311A and a second side surface portion 311B extending in the longitudinal direction of the first groove portion 310, a third side surface portion 311C connecting one ends of the first side surface portion 311A and the second side surface portion 311B, and a fourth side surface portion 311D connecting the other ends of the first side surface portion 311A and the second side surface portion 311B. The convex portion 312 extends together with the first side surface portion 311A and the second side surface portion 311B from one end portion 38A side (third side surface portion 311C side) to the other end portion 38B side (fourth side surface portion 311D side), excluding the portions of the third side surface portion 311C and the fourth side surface portion 311D disposed at both ends of the first groove portion 310.

[0021] Hereinafter, the structure and dimensions of the first groove portion 310 will be described using a cross-sectional view of the first groove portion 310 shown in FIG. 4 along a virtual plane orthogonal to the longitudinal direction of the first groove portion 310.

[0022] (The first side surface portion 311A and the second side surface portion 311B) The first side surface portion 311A and the second side surface portion 311B extend from the opening edge 301 of the curved surface portion 300 respectively, and the distance between them gradually decreases as it becomes deeper. The first side surface portion 311A and the second side surface portion 311B are each formed with a linear cross-section. Although not shown in the figure, the cross-sectional shapes of the first side surface portion 311A and the second side surface portion 311B are not limited to being linear, and may be formed in a curved shape. Also, the portions where the first side surface portion 311A and the second side surface portion 311B are connected to the curved surface portion 300 may be formed to curve in a convex shape protruding outward. Further, the portions where the first side surface portion 311A and the second side surface portion 311B are connected to the convex portion 312 may be formed to curve in a concave shape recessed toward the can central axis.

[0023] The end at the deep position of the first side surface portion 311A and the end at the deep position of the second side surface portion 311B are connected to the convex portion 312, and the point P13 where the end at the deep position of the first side surface portion 311A is connected to the convex portion 312 constitutes the deepest portion (hereinafter referred to as the deepest part) of the first groove portion 310. The maximum depth D11 is, for example, 0.10 mm or more and 0.30 mm or less. The maximum depth D11 is the depth from the virtual straight line L1 that connects the point P11 where the first side surface portion 311A is connected to the opening edge 301 of the curved surface portion 300 and the point P12 where the second side surface portion 311B is connected to the opening edge 301 of the curved surface portion 300 in the cross-section of the first groove portion 310, and is orthogonal to this straight line L1 and orthogonal to the longitudinal direction of the first groove portion 310. In FIG. 5, the straight line L1 is shown by a dashed line, and the straight line L1 is substantially the same as the virtual cylindrical surface. If the maximum depth D11 of the first groove portion 310 is less than 0.10 mm, the visibility of the groove portion deteriorates, and if it is deeper than 0.30 mm, it cannot be processed, which is not preferable.

[0024] Note that the point P14 where the end at the deep position of the second side surface portion 311B is connected to the convex portion 312 is set to the same depth as the point P13 where the end at the deep position of the first side surface portion 311A is connected to the convex portion 312. Also, the first side surface portion 311A and the second side surface portion 311B are formed with a linear or curved cross-section.

[0025] The width W11 of the first groove portion 310 is, for example, 2.00 mm or more and 4.00 mm or less. If the width W11 of the first groove portion 310 is less than 2.00 mm, it cannot be processed. If the width of the first groove portion is greater than 4.00 mm, the visibility of the groove portion deteriorates, which is not preferable. Note that the width W11 corresponds to the length of the straight line L1 from the point P11 to the point P12.

[0026] (Convex portion 312) The convex portion 312 protrudes from the deepest part of the first side surface portion 311A and the deepest part of the second side surface portion 311B (the deepest part of the first groove portion 310) toward the virtual cylindrical surface (straight line L1). The dimension H11 by which the convex portion 312 protrudes from the deepest part of the first groove portion 310 toward the virtual cylindrical surface (straight line L1) is set to be smaller than the maximum depth D11 of the first groove portion 310. The dimension H11 by which the convex portion 312 protrudes is, for example, 0.05 mm or more and 0.15 mm or less. The dimension H11 is the height from the deepest part to the highest part of the convex portion 312 in a direction orthogonal to the straight line L1 and orthogonal to the longitudinal direction of the first groove portion 310. If the height H11 of the convex portion 312 is less than 0.05 mm, deformation of the first groove portion 310 and its periphery cannot be prevented.

[0027] Further, the convex portion 312 has an outer surface formed as a convex curved surface protruding toward the virtual cylindrical surface (straight line L1) and an inner surface formed as a concave curved surface recessed toward the virtual cylindrical surface (straight line L1), and has a semi-circular arc-shaped cross section. The width W12 of the convex portion 312 is, for example, 0.50 mm or more. Note that the width W12 is the straight-line distance between the point P13 where the end at the deep position of the first side surface portion 311A is connected to the convex portion 312 and the point P14 where the end at the deep position of the second side surface portion 311B is connected to the convex portion 312.

[0028] Next, with reference to FIGS. 5 and 6, the cross-sectional structure in the longitudinal direction of the first groove portion 310 will be described. FIG. 6 shows a cross-sectional shape of the first groove portion 310 along a virtual plane extending in the longitudinal direction of the first groove portion 310. In FIG. 5, the virtual plane is represented by a dashed line L2, and the longitudinal direction of the first groove portion 310 is represented by an arrow DR1. The third side surface portion 311C extends from the opening edge 301 of the curved surface portion 300 to the convex portion 312 and is formed with a linear cross-section. The acute angle θ1 formed between the third side surface portion 311C and the curved surface portion 300 is, for example, 90 degrees or more and 170 degrees or less.

[0029] One end portion 312A of the convex portion 312 has an arcuate cross-section and is curved outward in a convex shape that protrudes. Although not shown, the fourth side surface portion 311D is also curved outward in a convex shape similar to the third side surface portion 311C. The convex portion 312 is formed with a linear cross-section except for one end portion 312A and the opposite end portion thereof, and the first side surface portion 311A and the second side surface portion 311B also have linear cross-sections along the longitudinal direction of the first groove portion 310.

[0030] (Second groove portion 320) As shown in FIG. 1, the second groove portion 320 is formed in an elliptical shape that is long vertically in a front view of the can body 10. Specifically, the second groove portion 320 includes a lower end portion 320A formed near the can bottom portion 20, an upper end portion 320B formed near the reduced diameter portion 40 and arranged vertically with the lower end portion 320A, a first intermediate end portion 320C that constitutes a location that is furthest from the straight line L3 in the circumferential direction when assuming a virtual straight line L3 connecting the lower end portion 320A and the upper end portion 320B, and a second intermediate end portion 320D that constitutes a location that is furthest from the straight line L3 in the direction opposite to the circumferential direction. Further, in the second groove portion 320, an arcuate portion 320E that extends in an arcuate shape is formed between the lower end portion 320A or the upper end portion 320B and the first intermediate end portion 320C or the second intermediate end portion 320D. As shown in FIG. 7, the cross-sectional shapes of the lower end portion 320A, the upper end portion 320B, the first intermediate end portion 320C, or the second intermediate end portion 320D along a virtual plane orthogonal to the longitudinal direction in which the second groove portion 320 extends are different from the cross-sectional shape of the first groove portion 310, and are formed by a first side surface portion 321 and a second side surface portion 322 that extend from the annular edges 303A and 303B of the curved surface portion 300 and whose distance from each other gradually decreases as it becomes deeper.

[0031] The first side surface portion 321 and the second side surface portion 322 each have a linear cross-section. Although not shown, the cross-sectional shapes of the first side surface portion 321 and the second side surface portion 322 are not limited to being linear and may be formed in a curved shape. Also, the portions where the first side surface portion 321 and the second side surface portion 322 connect to the curved surface portion 300 may be formed to curve in a convex shape that protrudes outward. Further, the portion where the first side surface portion 321 and the second side surface portion 322 connect may be formed to curve in a concave shape that is recessed toward the can central axis.

[0032] In the second groove portion 320, the portion where the first side surface portion 321 and the second side surface portion 322 connect constitutes the deepest part, and the maximum depth D2 is, for example, 0.10 mm or more and 0.30 mm or less. The maximum depth D2 is the depth from a virtual straight line L2 that connects a point P21 where the first side surface portion 321 connects to the edge 303B of the curved surface portion 300 and a point P22 where the second side surface portion 322 connects to the edge 303A of the curved surface portion 300 in the cross-section of the second groove portion 320, is orthogonal to this straight line L2, and is orthogonal to the longitudinal direction of the second groove portion 320. In FIG. 7, the straight line L2 is shown as a dashed-dotted line. The width W21 of the second groove portion 320 is, for example, 2.00 mm or more and 4.00 mm or less.

[0033] (Arc-shaped portion 320E) The cross-sectional shape of the arc portion 320E may be configured in a V-shaped or U-shaped cross-section by the first side surface portion 321 and the second side surface portion 322, similar to the lower end portion 320A, the upper end portion 320B, the first intermediate end portion 320C, and the second intermediate end portion 320D. Preferably, in the arc portion 320E, a portion in the middle of its longitudinal direction has a lower strength against the load from above or from below compared to the lower end portion 320A, the upper end portion 320B, the first intermediate end portion 320C, and the second intermediate end portion 320D. Therefore, the second reinforcing portion is formed at a portion in the middle of the longitudinal direction of the arc portion 320E. In this case, the cross-sectional shape of the second groove portion 320 along a virtual plane orthogonal to the longitudinal direction of the arc portion 320E is composed of the first side surface portion 321, the second side surface portion 322, and the second reinforcing portion provided between them, as shown in FIG. 6. For example, a convex portion 323 as the second reinforcing portion protrudes from the deep positions P23 and P24 of the first side surface portion 321 and the second side surface portion 322 toward the virtual cylindrical surface. The dimension H21 by which this convex portion 323 protrudes from the deepest part of the second groove portion 320 to the virtual cylindrical surface (straight line L2) is set to be smaller than the maximum depth D2 of the second groove portion 320, and the dimension H21 by which the convex portion 323 protrudes is, for example, 0.05 mm or more. The width W22 of the convex portion 323 is, for example, 0.50 mm or more. Further, in the second groove portion 320 of the embodiment, the first intermediate end portion 320C and the second intermediate end portion 320D are reinforced by the convex portion 323 (second reinforcing portion). Also in the first intermediate end portion 320C and the second intermediate end portion 320D, the convex portion 323 is also provided between the first side surface portion 321 and the second side surface portion 322, and the convex portion 323 extends in the longitudinal direction of the first intermediate end portion 320C and the second intermediate end portion 320D together with the first side surface portion 321 and the second side surface portion 322.

[0034] In the can body portion 30, the curved surface portion 300 provided outside the second groove portion 320 is provided with a plurality of first groove portions 310 beside the arc portion 320E. Further, as shown in FIG. 6, in the can body portion 30, the first groove portion 310 and the second groove portion 320 are close to each other, and the curved surface portion 300 is formed between one end portion 38A of the first groove portion 310 and the second groove portion 320. At the location where one end portion 38A of the first groove portion 310 and the second groove portion 320 are close to each other, the longitudinal direction DR1 of the first groove portion 310 and the longitudinal direction DR2 of the second groove portion 320 are non-parallel. Further, the convex portion 323 (second reinforcing portion) of the arcuate portion 320E of the second groove portion 320 is formed on the extension of the convex portion 312 (first reinforcing portion) of the first groove portion 310.

[0035] The can body 10 is not limited to the material, but is made of, for example, a 3000 series aluminum alloy material. An example of a method for manufacturing the bottomed cylindrical can body 10 will be described below. The can body 10 is manufactured by sequentially performing a punching and capping process, a DI process, a trimming process, a printing process, a coating process, a groove forming process, a necking process, and a flanging process.

[0036] [Punching Process and Capping Process (Drawing Process)] After performing hot rolling, cold rolling, and annealing on an ingot made of an aluminum alloy material to form an intermediate plate material with a predetermined plate thickness, a rolled material with a final plate thickness is prepared by performing cold finish rolling on the intermediate plate material. In the punching process and the capping process, the rolled material is drawn (capped) while being punched by a capping press. Thereby, a relatively large-diameter and shallow cup-shaped body is formed.

[0037] [DI Process (Drawing Ironing Process)] In the DI process, the cup-shaped body is subjected to DI processing (re-drawing and ironing processing) by a DI processing apparatus to form a bottomed cylindrical intermediate formed body including a cylindrical can body portion to be formed and a can bottom portion. By this DI processing, the can bottom portion of the intermediate formed body is formed into the can bottom shape of the final can body 10.

[0038] [Trimming Process] At the open end of the intermediate molded body formed by the DI processing device, ears are formed and the height is uneven. Therefore, in the trimming process, the open end of the intermediate molded body is cut and aligned.

[0039] [Printing process, painting process] In the printing process, after washing the intermediate molded body that has undergone the trimming process and removing lubricating oil and the like, surface treatment is performed and dried. Then, outer surface printing and outer surface painting are performed, and then inner surface painting is performed. Next, in the painting process, after performing outer surface painting, inner surface painting is performed. Specifically, for example, using a polyester-based paint, the outer surface of the planned can body part of the intermediate molded body is painted, and the intermediate molded body with this outer surface painting is heated and dried in an oven. Then, for example, using an epoxy-based paint, the inner surfaces of the planned can body part and the can bottom of the intermediate molded body are painted, and the intermediate molded body with this inner surface painting is heated and dried in an oven while being conveyed by a conveyor.

[0040] [Groove forming process] In the groove forming step, a first groove portion and a second groove portion are formed in a planned can body portion using an embossing device. The embossing device includes a first rotating body disposed inside the intermediate molded body and a second rotating body disposed outside the intermediate molded body. On the first rotating body, a linear first concave portion for forming the first groove portion and an annular second concave portion for forming the second groove portion are formed as portions recessed from the outer peripheral surface toward the rotation axis. On the second rotating body, a linear first convex portion for forming the first groove portion and an annular second convex portion for forming the second groove portion are formed as portions protruding radially outward from the outer peripheral surface. With the first rotating body in contact with the inner peripheral surface of the planned can body portion of the intermediate molded body, the first rotating body rotates together with the intermediate molded body, and the second rotating body also rotates in conjunction with these rotations. In the process of these rotations, the cylindrical planned can body portion is sandwiched between the first rotating body and the second rotating body, and at the sandwiched portion, the first convex portion enters the corresponding first concave portion, and the planned can body portion is embossed. Thereby, the first groove portion 310 is formed. Also, the second convex portion enters the corresponding second concave portion, and the portion sandwiched between the second convex portion and the second concave portion in the planned can body portion is embossed. Thereby, the second groove portion 320 is formed. The first groove portion and the second groove portion are formed at a position excluding the upper portion on the opening end side where the necking step is performed among the cylindrical portions of the planned can body portion.

[0041] [Necking step] In the necking step, a necking die (punch and die) is fitted inside and outside the upper portion of the intermediate molded body, and a diameter reduction process is performed between the punch and the die to reduce the diameter of the opening end portion of the intermediate molded body upward, thereby forming a diameter reduction portion 40. Also, by this diameter reduction process, a cylindrical neck and a planned flange portion are formed on the diameter reduction portion 40.

[0042] [Flanging step] In the flanging step, among the neck and the planned flange portion located at the opening end portion of the intermediate molded body, a flange portion 60 that protrudes radially outward toward the opening side and extends along the circumferential direction is formed. Also, among the neck and the planned flange portion, a cylindrical portion having a constant diameter is left as it is without being processed to form a neck portion 50.

[0043] The can body 10 is completed through the flanging process. The can body 10 is conveyed to the subsequent process. In this subsequent process, the can body 10 is filled with contents such as beverages, and a can lid is wound around the flange portion 60 to seal the can body 10, completing the can product.

[0044] Here, FIG. 8 is a front view of the can body 200 of the comparative example. The cylindrical can body portion 230 of the can body 200 is provided with a groove portion 270 formed in an elliptical shape that is concave toward the central axis from the cylindrical curved surface portion 210 and is long in the vertical direction. This groove portion 270 includes an arcuate portion 270E formed between the lower end portion 270A near the bottom portion 220 or the upper end portion 270B near the reduced-diameter portion 240 and the first intermediate end portion 270C or the second intermediate end portion 270D. Since the middle portion in the longitudinal direction of each arcuate portion 270E is weaker in strength than the lower end portion 270A, etc., it tends to be prone to buckling under a load from above or a load from below.

[0045] On the other hand, in the can body 10 of the present embodiment, the convex portion 312 (first reinforcing portion) of the first groove portion 310 is formed at a circumferential position or a position opposite to the circumferential direction with respect to the convex portion 323 (second reinforcing portion) of the second groove portion 320, and the convex portion 323 of the second groove portion 320 is formed on the extension of the convex portion 312 of the first groove portion 310. Thus, the rigidity of the can body portion 30, particularly the arcuate portion 320E and the surrounding portions including this arcuate portion 320E, can be enhanced. Thereby, when attaching the can lid to the can body 10 filled with the contents, a load associated with the process of winding the peripheral edge of the can lid around the flange portion 60 acts on the can body portion 30. However, since the can body portion 30 is reinforced, buckling of the can body portion 30, particularly the arcuate portion 320E, can be prevented. Also, when applying a mold to the intermediate formed body and reducing the diameter of the cylindrical opening side in the necking process, deformation of the portion that becomes the can body portion can be suppressed. Even in a can product with a can lid attached to the can body 10 filled with the contents, buckling of the can body portion 30 can be prevented.

[0046] (Modification of the First Embodiment) The can body of the modified example of the first embodiment includes a first groove portion 310A instead of the first groove portion 310 of the first embodiment. As shown in FIG. 9, in a cross section along a virtual plane orthogonal to the longitudinal direction of the first groove portion 310A, a convex portion 314 having a different shape from the convex portion 312 is disposed between the first side surface portion 311A and the second side surface portion 311B compared to the first groove portion 310. The same components as those in the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[0047] The convex portion 314 includes a first protruding side surface portion 314A extending from an end at a deep position of the first side surface portion 311A toward the virtual cylindrical surface (straight line L1), a second protruding side surface portion 314B extending from an end at a deep position of the second side surface portion 311B toward the virtual cylindrical surface (straight line L1), and an upper bottom portion 314C connecting the end of the first protruding side surface portion 314A on the virtual cylindrical surface (straight line L1) side and the end of the second protruding side surface portion 314B on the virtual cylindrical surface (straight line L1) side.

[0048] A point P13 where the end at a deep position of the first side surface portion 311A and the end at a deep position of the first protruding side surface portion 314A are connected constitutes the deepest part of the first groove portion 310. The maximum depth D11 is, for example, 0.10 mm or more and 0.30 mm or less. Note that a point P14 where the end at a deep position of the second side surface portion 311B and the end at a deep position of the second protruding side surface portion 314B are connected is set at the same depth as the point P13.

[0049] (The first protruding side surface portion 314A and the second protruding side surface portion 314B) The first protruding side surface portion 314A and the second protruding side surface portion 314B are respectively formed by extending from the end at a deep position of the first side surface portion 311A and the end at a deep position of the second side surface portion 311B, and the distance between them gradually decreases as they become shallower. The first protruding side surface portion 314A and the second protruding side surface portion 314B each have a linear cross section.

[0050] (The upper bottom portion 314C) The upper bottom portion 314C has a linear cross-section, and the surface on the side of the virtual cylindrical surface (straight line L1) is formed flat, and this flat surface constitutes the deepest part to the highest point. The protruding dimension H11 of the upper bottom portion 314C is, for example, not less than 0.05 mm and not more than 0.15 mm.

[0051] The width W13 of the convex portion 314 is, for example, not less than 0.50 mm. The width W13 is the straight-line distance between a point P13 where the end at the deep position of the first side surface portion 311A and the end at the deep position of the first protruding side surface portion 314A are connected, and a point P14 where the end at the deep position of the second side surface portion 311B and the end at the deep position of the second protruding side surface portion 314B are connected. As described above, the cross-section of the convex portion 314 along a virtual plane orthogonal to the longitudinal direction is formed in a square shape.

[0052] In the can body of the modification of the first embodiment, since the first groove portion 310A includes the convex portion 314 (first reinforcing portion), the rigidity of the can body portion 30 can be increased in the same manner as the can body 10 of the first embodiment.

[0053] (Second Embodiment) The can body of the second embodiment includes a first groove portion 310B instead of the first groove portion 310 of the first embodiment. As shown in FIG. 10, in the cross-section along a virtual plane orthogonal to the longitudinal direction of the first groove portion 310B, compared with the first groove portion 310, as a first reinforcing portion, instead of the convex portion 312, a concave portion 315 recessed toward the can central axis C is disposed between the first side surface portion 311A and the second side surface portion 311B. The same components as those in the configuration of the first embodiment are denoted by the same reference numerals, and the description thereof is omitted.

[0054] The recess 315 is recessed from the deepest part of the first side surface portion 311A and the deepest part of the second side surface portion 311B toward the can central axis C, and constitutes a portion deeper than the end at the deep position of the first side surface portion 311A and the end at the deep position of the second side surface portion 311B. The ends at the deep positions of the first side surface portion 311A and the second side surface portion 311B are set to the same depth D12, and the depth D12 is, for example, 0.10 mm or more and 0.30 mm or less. The depth D12 is the depth from the straight line L1 in a direction orthogonal to the straight line L1 and orthogonal to the longitudinal direction of the first groove portion 310B. If the depth D12 of the ends at the deep positions of the first side surface portion 311A and the second side surface portion 311B is less than 0.10 mm, the visibility of the groove portion deteriorates, and if it is deeper than 0.30 mm, it cannot be processed, which is not preferable.

[0055] The recess 315 has an outer surface formed on a concave curved surface that is recessed toward the can central axis C and an inner surface formed on a convex curved surface that protrudes toward the can central axis C, and the cross section is formed in an arc shape of a semi-circle.

[0056] The outer surface of the recess 315 constitutes the deepest part, and the maximum depth D13 is, for example, 0.15 mm or more and 0.45 mm or less. The maximum depth D13 is the depth from the straight line L1 in a direction orthogonal to the straight line L1 and orthogonal to the longitudinal direction of the first groove portion 310B. Further, if the maximum depth D13 of the recess 315 is less than 0.15 mm, buckling of the can body cannot be prevented, and if it is deeper than 0.45 mm, it cannot be processed, which is not preferable.

[0057] The width W14 of the recess 315 is, for example, 0.50 mm or more. The width W14 is the straight-line distance between the point P13 where the end at the deep position of the first side surface portion 311A is connected to the recess 315 and the point P14 where the end at the deep position of the second side surface portion 311B is connected to the recess 315. Although not shown, the recess 315 may be formed with a square cross section along a virtual plane orthogonal to the longitudinal direction, like the convex portion 314.

[0058] The can body of the second embodiment includes a first groove portion 310B having a concave portion 315 (first reinforcing portion), and a second groove portion 320 having a convex portion 323 (second reinforcing portion) at a circumferential position or in a direction opposite to the circumferential direction with respect to these. By forming the convex portion 323 of the second groove portion 320 on the extension of the concave portion 315 of the first groove portion 310B, the rigidity of the can body portion 30 can be increased in the same manner as the can body 10 of the first embodiment.

[0059] (Third Embodiment) The can body of the third embodiment includes a first groove portion 310C instead of the first groove portion 310 of the first embodiment. As shown in FIG. 11, in a cross section along a virtual plane orthogonal to the longitudinal direction of the first groove portion 310C, compared with the first groove portion 310, as a first reinforcing portion, instead of the convex portion 312, an uneven portion 316 is disposed between the first side surface portion 311A and the second side surface portion 311B. The same components as those in the configuration of the first embodiment and the like are denoted by the same reference numerals, and the description thereof is omitted.

[0060] The uneven portion 316 constitutes a shallower portion between the end at a deeper position of the first side surface portion 311A and the end at a deeper position of the second side surface portion 311B, and a deeper portion between the end at a deeper position of the first side surface portion 311A and the end at a deeper position of the second side surface portion 311B between the first side surface portion 311A and the second side surface portion 311B. The end at a deeper position of the first side surface portion 311A and the end at a deeper position of the second side surface portion 311B are set to the same depth D13, and the depth D13 is, for example, 0.10 mm or more and 0.30 mm or less. The depth D13 is the depth from the straight line L1 in a direction orthogonal to the straight line L1 and orthogonal to the longitudinal direction of the first groove portion 310C.

[0061] The uneven portion 316 includes convex portions 316A and 316B protruding toward the virtual cylindrical surface (straight line L1), and a concave portion 316C disposed between these convex portions 316A and 316B and recessed toward the can central axis C. The convex portions 316A and 316B and the concave portion 316C are arranged in the groove width direction orthogonal to the longitudinal direction of the first groove portion 310C, and the outer surface and the inner surface are formed in an uneven shape.

[0062] The convex portions 316A and 316B protrude from the end at a deep position of the first side surface portion 311A toward the virtual cylindrical surface (straight line L1). The dimension H12 by which the convex portions 316A and 316B protrude from the first side surface portion 311A to the virtual cylindrical surface (straight line L1) is set to be smaller than the depth D13 of the end at the deep position of the first side surface portion 311A. The dimension H12 by which the convex portions 316A and 316B protrude is, for example, 0.05 mm or more and 0.15 mm or less. The dimension H12 is the height from the deepest part to the highest part of the convex portions 316A and 316B in a direction orthogonal to the straight line L1 and also orthogonal to the longitudinal direction of the first groove portion 310C. Further, the convex portions 316A and 316B have an outer surface formed as a convex curved surface protruding toward the virtual cylindrical surface (straight line L1) and an inner surface formed as a concave curved surface recessed toward the virtual cylindrical surface (straight line L1), and the cross section is formed in an arc shape of a semi-circle. Note that the convex portion 316B is formed in the same shape as the convex portion 316A.

[0063] The concave portion 316C has an outer surface formed as a concave curved surface recessed toward the can central axis C and an inner surface formed as a convex curved surface protruding toward the can central axis C, and the cross section is formed in an arc shape of a semi-circle. The outer surface of the concave portion 316C constitutes the deepest part of the first groove portion 310C, and the maximum depth D14 is, for example, 0.10 mm or more and 0.40 mm or less. The maximum depth D14 is the depth from the straight line L1 in a direction orthogonal to the straight line L1 and also orthogonal to the longitudinal direction of the first groove portion 310C.

[0064] The width W15 of the concavo-convex portion 316 is, for example, 0.50 mm or more. Note that the width W15 is the straight-line distance between the point P13 where the end at the deep position of the first side surface portion 311A is connected to the concavo-convex portion 316 and the point P14 where the end at the deep position of the second side surface portion 311B is connected to the concavo-convex portion 316.

[0065] The can body of the third embodiment includes the first groove portion 310C having the concavo-convex portion 316 (first reinforcing portion), and the second groove portion 320 has the convex portion 323 (second reinforcing portion) at a circumferential position or a position opposite to the circumferential direction with respect to these. Since the convex portion 323 of the second groove portion 320 is formed on the extension of the concavo-convex portion 316 of the first groove portion 310C, the rigidity of the can body portion 30 can be increased in the same manner as the can body 10 of the first embodiment.

[0066] (Fourth Embodiment) The can body of the fourth embodiment includes a first groove portion 310D instead of the first groove portion 310 of the first embodiment. As shown in FIG. 12, in a cross-section along a virtual plane orthogonal to the longitudinal direction, the first groove portion 310D includes a concave portion 317 that constitutes the deepest part instead of the convex portion 312 compared with the first groove portion 310. The concave portion 317 is connected to the first side surface portion 311A via a shallow bottom portion 318A formed flat, and further, the concave portion 317 is connected to the second side surface portion 311B via a shallow bottom portion 318B. The same components as those in the configuration of the first embodiment and the like are denoted by the same reference numerals, and the description thereof is omitted.

[0067] The shallow bottom portions 318A and 318B are each formed with a linear cross-section and are further provided at a depth D15. The depth D15 is, for example, 0.10 mm or more and 0.30 mm or less. This depth D15 is the depth from the straight line L1 in a direction orthogonal to the straight line L1 and orthogonal to the longitudinal direction of the first groove portion 310D.

[0068] The concave portion 317 includes a first deep bottom side surface portion 317A extending in a groove depth direction in which a groove becomes deeper from an end of one of the shallow bottom portions 318A toward the virtual cylindrical surface, a second deep bottom side surface portion 317B extending in the groove depth direction from an end of the other shallow bottom portion 318B, and a deep bottom portion 317C connecting an end at a deep position of the first deep bottom side surface portion 317A and an end at a deep position of the second deep bottom side surface portion 317B. The first deep bottom side surface portion 317A and the second deep bottom side surface portion 317B gradually decrease in interval as they become deeper. The deep bottom portion 317C is formed with a linear cross-section, and the flat outer surface constitutes the deepest part of the first groove portion 310D. The maximum depth D16 is, for example, 0.10 mm or more and 0.70 mm or less. This depth D16 is the depth from the straight line L1 in a direction orthogonal to the straight line L1 and orthogonal to the longitudinal direction of the first groove portion 310D.

[0069] The width W16 of the recess 317 is, for example, 0.10 mm or more. The width W16 is the straight-line distance between a point P13 where one shallow bottom portion 318A is connected to the recess 317 and a point P14 where the other shallow bottom portion 318A is connected to the recess 317. Compared with the recess 315 of the second embodiment in FIG. 10, the recess 317 is formed with a square cross-section.

[0070] The can body of the fourth embodiment includes a first groove portion 310D having a recess 317 (first reinforcing portion), and a second groove portion 320 having a convex portion 323 (second reinforcing portion) at a circumferential position or in a direction opposite to the circumferential direction with respect to these. Since the convex portion 323 of the second groove portion 320 is formed on the extension of the recess 317 of the first groove portion 310D, the rigidity of the can body portion 30 can be increased in the same manner as the can body 10 of the first embodiment.

[0071] The present invention can be implemented without being limited to the above description and illustrated examples.

[0072] In the can body of the above-described embodiment, as shown in FIG. 5, the curved surface portion 300 is disposed between the first groove portion 310 and the second groove portion 320. However, as shown in FIG. 13, one end portion 38A of the first groove portion 310 is adjacent to the arcuate portion 320E of the second groove portion 320, and may also be adjacent to the first intermediate end portion or the second intermediate end portion. In this case, although not shown, the plurality of first groove portions 310 extend radially from the second groove portion 330. FIG. 14 is a cross-sectional shape of the can body along a virtual plane extending in the longitudinal direction of the first groove portion 310 in FIG. 13. In FIG. 13, the virtual plane is represented by a dashed line L2. The third side surface portion 311C of the first groove portion 310 and the first side surface portion 321 of the arcuate portion 320E are connected to form a corner portion 325 protruding toward the virtual cylindrical surface. The acute angle θ2 formed by the third side surface portion 311C and the first side surface portion 321 is, for example, 1 degree or more and 179 degrees or less. The length C in the longitudinal direction DR2 of the arcuate portion 320E of this corner portion 325 corresponds to the width W11 of the first groove portion 310 and is, for example, 2.00 mm or more and 4.00 mm or less. Even at the location where the first groove portion 310 and the arcuate portion 320E are adjacent in this way, when a load F in the longitudinal direction acts on the first groove portion 310, the deformation of the first groove portion 310 and its periphery due to the load F can be prevented by the convex portion 312 (first reinforcing portion) provided in the first groove portion 310.

[0073] (concavo-convex portion) The number and shape of the convex portions and concave portions constituting the concavo-convex portion are not limited to the illustrated examples. For example, it may be formed in a concavo-convex shape with two concave portions and one concave portion provided between these concave portions. Further, the concavo-convex portion is not limited to a combination of a convex portion and a concave portion, and may be formed by combining convex portions or combining concave portions.

[0074] For example, as shown in FIG. 15, when the uneven portion 316D is formed by combining the convex portions 314, in the cross-section of the uneven portion 316D along a virtual plane orthogonal to the longitudinal direction of the first groove portion, a recessed portion is formed between the convex portions 314. The deepest part of this recess is formed by a connecting portion 316E disposed between the two convex portions 314 and connecting them. The connecting portion 316E is disposed at the same depth as the deepest depth D11 of the first groove portion formed by the end at the deep position of the first side surface portion 311A and the end at the deep position of the second side surface portion 311B. Alternatively, the connecting portion 316F disposed between the two convex portions 314 and connecting them may be at a position shallower than the deepest depth D11 of the first groove portion as shown by the dashed line and may be set at a position lower than the upper bottom portion 314C. The cross-section of the connecting portions 316E and 316F is not limited to the linear shape shown in the figure, and may be curved, for example, so as to be recessed toward the can central axis C. Although not shown, the uneven portion may be configured by arranging convex portions 312 having a semi-circular arc cross-section in the groove width direction orthogonal to the longitudinal direction of the first groove portion via the connecting portions 316E and 316F instead of the convex portions 314 having a rectangular cross-section.

[0075] For example, as shown in FIG. 16, when the uneven portion 316H is formed by combining the concave portions 317, in the cross-section of the uneven portion 316H along a virtual plane orthogonal to the longitudinal direction of the first groove portion, a portion protruding toward the virtual cylindrical surface is formed between the concave portions 317. The highest part of this protruding portion is formed by a connecting portion 316J disposed between the two concave portions 317 and connecting them. The connecting portion 316J is disposed at the same depth as the depth D12 formed by the end at the deep position of the first side surface portion 311A and the end at the deep position of the second side surface portion 311B. Alternatively, the connecting portion 316K disposed between the two concave portions 317 and connecting them may be at a position deeper than the depth D12 of the end at the deep position of the first side surface portion 311A as shown by the dashed line and may be set at a position higher than the bottom portion 317C. The cross-section of the connecting portions 316J and 316K is not limited to the linear shape shown in the figure, and may be curved, for example, so as to protrude toward the virtual cylindrical surface. Although not shown, the uneven portion may be configured by arranging concave portions 315 having a semi-circular arc cross-section in the groove width direction orthogonal to the longitudinal direction of the first groove portion via the connecting portions 316J and 316K instead of the concave portions 317 having a rectangular cross-section.

[0076] (Shallow bottom) As shown in FIG. 17, the uneven portion 316 may also be connected via the first side surface portion 311A and the shallow bottom portion 318A, and may be connected via the second side surface portion 311B and the shallow bottom portion 318B. Further, as shown in FIG. 18, the convex portion 314 may be connected via the first side surface portion 311A and the bottom portion 318C formed with a straight cross section, and may be connected via the second side surface portion 311B and the bottom portion 318D formed with a straight cross section. When the bottom portion 318C and the bottom portion 318C are arranged at the same depth, they constitute the deepest portion. When the bottom portion 318C and the bottom portion 318C have different depths, the deeper one of them constitutes the deepest portion. The concave portion and the uneven portion are not limited to the case of being connected via both the first side surface portion and the second side surface portion and the shallow bottom portion, and may be connected via one of the first side surface portion and the second side surface portion and the shallow bottom portion. The convex portion is also not limited to the case of being connected via both the first side surface portion and the second side surface portion and the bottom portion, and may be connected via one of the first side surface portion and the second side surface portion and the bottom portion.

[0077] (Convex portion) As shown in FIG. 19, the convex portion 319 is formed with a large arc in cross-sectional shape as compared with the convex portion 312 in FIG. 4, and the highest portion of the convex portion 319 is in contact with the virtual cylindrical surface. In this case, there is an advantage of excellent workability. Although not shown, the upper bottom portion 314C of the convex portion 314 and the convex portions 316A and 316B of the uneven portion may also have their highest portions arranged on the virtual cylindrical surface. In the above-described embodiment, the cross section of the upper bottom portion 314C of the convex portion 314 is formed in a straight line, but the cross section of the upper bottom portion 314C may be curved. The cross-sectional shape of the deep bottom portion 317C of the concave portion 317 shown in FIG. 12 is not limited to a straight line and may also be curved.

[0078] (First side surface portion 311A and second side surface portion 311B) The case where the ends at the deep positions of the first side surface portion 311A and the second side surface portion 311B are arranged at the same depth has been described, but these depths may be different.

[0079] (Arrangement of the first groove portion) In the above embodiment, a plurality of first grooves are arranged radially extending around the second groove. However, the arrangement of the plurality of first grooves is not limited to the arrangement in which all the first grooves extend radially from or around the second groove. For example, among the plurality of first grooves, some may extend radially with one end approaching the second groove, and the remaining first grooves may be arranged at positions away from the second groove and extend non-radially. Further, the first groove may be formed as a vertical groove extending parallel to the can central axis from the second groove. The plurality of first grooves may be formed as horizontal grooves extending in the circumferential direction from the second groove. Or the plurality of first grooves may be arranged with one end approaching the second groove, and one end and the other end are inclined at a predetermined angle around the can central axis, and this angle may be formed as an inclined groove set to be the same for each first groove. Such a plurality of vertical grooves, horizontal grooves, and inclined grooves may be provided on the can body without being directly connected.

[0080] (Second groove) The case where the second reinforcing portion is not provided at the locations of the second groove in the above embodiment, for example, the lower end portion, the upper end portion, the first intermediate end portion, the second intermediate end portion, and the arc-shaped portion are configured to have a V-shaped cross-section or a U-shaped cross-section by the first side surface portion and the second side surface portion is shown. However, the cross-sectional shape of the location where the second reinforcing portion is not provided in the second groove 330 shown in FIG. 20 may be configured by arranging a bottom portion 327 between the first side surface portion 321 and the second side surface portion 322. The bottom portion 327 is formed flat, for example. The second reinforcing portion provided in the second groove is not limited to the convex portion 323 shown in FIG. 6, and may be formed in the same manner as the first reinforcing portion of the first groove such as the concave portion shown in FIG. 10 and the concavo-convex portion shown in FIG. 11. Further, in the above embodiment, the case where the second groove is provided at the arc-shaped portion, the first intermediate end portion, and the second intermediate end portion of the second groove is shown. However, the second groove may also be provided at the upper end portion and the lower end portion, and these may be formed to be annularly continuous. The elliptical shape in the front view of the can body of the second groove in the above embodiment may be formed by changing the ratio of the length and width of the ellipse. Further, the lower end portion, the upper end portion, the first intermediate end portion, and the second intermediate end portion are not limited to being configured as the locations where the arc-shaped portions are connected, and may be formed as straight portions extending linearly or the like.

[0081] The second groove portion of the present invention may be provided with an arcuate portion. For example, the second groove portion 340 of the can body 10A shown in FIG. 21 includes a straight portion 341 extending linearly, an arcuate portion 342 extending from this straight portion 341, and a straight portion 343 extending linearly from this arcuate portion 342. The arcuate portion 342 has the other end portion 342B at a position shifted in the circumferential direction and upward from the position of one end portion 342A, and extends arcuately from one end portion 342A to the other end portion 342B. In the can body 10A, the first groove portion 310 is formed in the can body portion 30 in the vicinity of the arcuate portion 342, and the convex portion 312 (first reinforcing portion) of the first groove portion 310 can improve the strength of the arcuate portion 342 and its periphery. The first groove portion 310 may be formed at the position indicated by the chain line at two points instead of the position indicated by the solid line. Furthermore, the arcuate portion 342 is provided with a convex portion 323 (second reinforcing portion) beside (circumferential position) the convex portion 312 (first reinforcing portion) and on the extension of the convex portion 312 (first reinforcing portion), whereby the strength of the arcuate portion 342 and its periphery can be further improved. In addition, the second groove portion of the present invention may be formed in an annular shape with at least one arcuate portion provided therein. The positional relationship between one end portion and the other end portion of the arcuate portion is not limited to the illustrated example, and may be shifted in the circumferential direction or in the direction opposite to the circumferential direction, and may be shifted upward or downward. The second groove portion of the present invention may be composed of only one arcuate portion.

[0082] (Can body) As shown in FIG. 22, the can body 10B may be configured for a bottle can by providing a mouth portion 70 provided with a screw portion 71 and a curl portion 72 for screwing a cap on the opening end portion side. The can body of the present invention may be configured without providing the second groove portion. In this case, the first groove portion may be provided in the can body portion without directly connecting the above-mentioned longitudinal groove, transverse groove, inclined groove, or a plurality of these.

Explanation of reference numerals

[0083] 10, 10A, 10B Can body 20 Can bottom 21 Grounding portion 22 Diameter-expanded portion 30 Can body portion 300 Curved surface part 310, 310A, 310B, 310C, 310D First groove part 311A First side surface part 311B Second side surface part 312, 314, 316A, 316B, 319 Protrusion (first reinforcing part) 314A First protruding side surface part 314B Second protruding side surface part 314C Upper bottom part 315, 316C, 317 Recess (first reinforcing part) 316, 316D, 316H Concavo-convex part (first reinforcing part) 317A First deep bottom side surface part 317B Second deep bottom side surface part 317C Deep bottom part 318A, 318B Shallow bottom part 318C, 318D Bottom part 320, 330, 340 Second groove part 320A Lower end part 320B Upper end part 320C First intermediate end part 320D Second intermediate end part 320E, 342 Arc part 321 First side surface part 322 Second side surface part 323 Protrusion (second reinforcing part) 325 Corner part 327 Bottom part 342A One end part 342B The other end part 40 Reduced diameter part 50 Head part 60 Flange part 70 Mouth part C Can central axis

Claims

1. A can body formed in a bottomed cylindrical shape, comprising: a can bottom portion; a cylindrical can body portion extending upward from the upper end of the can bottom portion, wherein the can body portion includes: a curved surface portion disposed on a virtual cylindrical surface; and a first groove portion connected to the curved surface portion and recessed toward the can central axis from the virtual cylindrical surface, wherein the first groove portion includes: a first side surface portion and a second side surface portion whose intervals gradually decrease as the depth increases; and a first reinforcing portion disposed between the first side surface portion and the second side surface portion and extending in the longitudinal direction of the first groove portion together with the first side surface portion and the second side surface portion, wherein the first reinforcing portion is any one of a convex portion protruding toward the virtual cylindrical surface, a concave portion recessed toward the can central axis, and an uneven portion formed by arranging the convex portion and the concave portion side by side in the groove width direction orthogonal to the longitudinal direction of the first groove portion. The can body is characterized by this.

2. The convex portion is disposed between the first side surface portion and the second side surface portion, the width of the first groove portion is 2.00 mm or more and 4.00 mm or less, the maximum depth of the first groove portion is 0.10 mm or more and 0.30 mm or less, and the height of the convex portion from the deepest portion of the first groove portion is 0.05 mm or more. The can body according to claim 1 is characterized by this.

3. The concave portion is disposed between the first side surface portion and the second side surface portion, the width of the first groove portion is 2.00 mm or more and 4.00 mm or less, the depth of the end at the deep position of the first side surface portion and the second side surface portion is 0.10 mm or more and 0.30 mm or less, and the depth of the deepest portion of the concave portion is 0.15 mm or more and 0.45 mm or less. The can body according to claim 1 is characterized by this.

4. The can body further includes a second groove portion connected to the curved surface portion and recessed toward the can central axis from the virtual cylindrical surface, wherein the second groove portion includes an arcuate portion extending in an arcuate shape from one end to the other end, the other end of the arcuate portion is displaced in the circumferential direction or the direction opposite to the circumferential direction from the one end, and is provided at a position displaced upward or downward, and further, the first groove portion is provided adjacent to the arcuate portion or beside the arcuate portion with the curved surface portion interposed therebetween. The can body according to claim 1 is characterized by this.

5. The can body further includes an annular second groove portion connected to the curved surface portion and recessed toward the can central axis from the virtual cylindrical surface. The second groove portion has a lower end portion formed closer to the bottom of the can, an upper end portion formed at a position higher than the lower end portion, a first intermediate end portion constituting the portion that is circumferentially farthest from the lower end portion and the upper end portion, and a second intermediate end portion constituting the portion that is circumferentially farthest from the lower end portion and the upper end portion in the direction opposite to the circumferential direction. An arcuate portion that extends in an arcuate shape is formed between each of the lower end portion and the upper end portion and each of the first intermediate end portion and the second intermediate end portion. The can body according to claim 1, wherein the first groove portion is provided outside the second groove portion, adjacent to the arcuate portion or beside the arcuate portion with the curved surface portion interposed therebetween.

6. The arcuate portion of the second groove portion has a first side surface portion and a second side surface portion whose intervals gradually decrease as they become deeper, and a second reinforcing portion disposed between the first side surface portion of the second groove portion and the second side surface portion of the second groove portion and extending in the longitudinal direction of the second groove portion together with the first side surface portion and the second side surface portion of the second groove portion. The can body according to claim 4 or claim 5, wherein the second reinforcing portion is any one of a convex portion protruding toward the virtual cylindrical surface, a concave portion recessed toward the central axis of the can, and an uneven portion formed by arranging the convex portion of the second reinforcing portion and the concave portion of the second reinforcing portion in the groove width direction perpendicular to the longitudinal direction of the second groove portion.

Images