Lid body, method for manufacturing metal can, metal can, and battery

Abstract

A lid body (20) comprises a bottom plate section (21), a vertical wall section (22), and a flange section (23). An outer peripheral edge (24) of the flange section (23) includes a pair of first straight side sections (241, 241a, 241b), corner sections (243), and a pair of second straight side sections (242, 242a, 242b). When the length of the flange section (23) from the vertical wall section (22) to the outer peripheral edge (24) is defined as a flange width, the flange section (23) has a flange width WS in at least either the pair of first straight side sections (241, 241a, 241b) or the pair of second straight side sections (242, 242a, 242b) and has a flange width WC larger than the flange width WS at each of the corner sections (243). The flange width WS is 3.3 times or less the plate thickness (t2) of the vertical wall section (22).

Description

Lid, method for manufacturing metal can, metal can, and battery

[0001] The present disclosure relates to a lid for a metal can, a method for manufacturing a metal can using the lid, and a metal can and a battery.

[0002] In recent years, electric vehicles, including battery electric vehicles (BEVs) and hybrid electric vehicles (HEVs), have become increasingly popular. Electric vehicles use, for example, non-aqueous electrolyte secondary batteries. Electric vehicles generally include multiple batteries connected to each other to ensure high power output and high capacity.

[0003] In order to meet the need for extended driving range, electric vehicles and other vehicles require batteries with a higher energy density. For example, rectangular metal cans are used as the outer cans of on-board batteries. When the metal can is rectangular, the smaller the radius of curvature of the corners between the side walls of the metal can, the more densely the batteries can be arranged. This reduces the area of ​​the metal can per unit area in the battery mounting space, reducing the loss of battery mounting space and allowing for the expectation of a higher energy density.

[0004] Patent Document 1 discloses a prismatic sealed secondary battery. In the battery of Patent Document 1, the metal can serving as the outer can includes a bottomed rectangular cylindrical container (can body) and a lid. The lid includes a joint formed by raising the outer periphery of the lid. The can body and the lid are joined by welding an end face of the can body and an end face of the joint of the lid with the joint of the lid fitted inside the can body.

[0005] The battery described in Patent Document 2 also includes a bottomed rectangular cylindrical container (can body) and a lid. In Patent Document 2, the can body is formed by bending a single metal flat plate and welding the butt joints of the plate. The lid is placed on an end face of the can body and joined to the can body by welding.

[0006] JP 2003-346742 A JP 2013-8665 A

[0007] In Patent Document 1, the outer surface of the joint of the lid must be tightly fitted to the inner surface of the can body around the entire circumference. In this case, the radius of curvature of the corner of the joint of the lid is necessarily smaller than the radius of curvature of the corner between the side walls of the can body. Specifically, the radius of curvature of the inner surface of the corner of the joint of the lid is the radius of curvature of the outer surface of the corner of the can body minus the plate thickness of the can body and the plate thickness of the lid. Therefore, if the diameter of the corner of the can body is reduced, it becomes difficult to manufacture the lid by drawing a metal plate, etc. In other words, if the radius of curvature of the corner of the can body is small, the configuration of the lid in Patent Document 1 may not be applicable.

[0008] In Patent Document 2, the lid is generally flat. Therefore, the diameter of the corners of the can body can be reduced without particularly considering the impact on the manufacture of the lid. However, in Patent Document 2, when joining the can body and the lid, the lid is placed on the end surface of the can body. Therefore, it is difficult to determine the position of the lid relative to the can body, making the joining process between the can body and the lid difficult.

[0009] An object of the present disclosure is to provide a lid for a metal can that can be applied to a can body having a small radius of curvature at the corner portion and that can improve the workability of joining the can body and the lid.

[0010] The lid for a metal can according to the present disclosure comprises a bottom plate portion, a vertical wall portion, and a flange portion. The vertical wall portion is continuous with the peripheral edge of the bottom plate portion. The flange portion is continuous with the vertical wall portion on the opposite side of the bottom plate portion. The flange portion protrudes from the vertical wall portion toward the outer periphery of the vertical wall portion. The flange portion surrounds the bottom plate portion in a plan view of the lid. The outer periphery of the flange portion includes a pair of opposing first straight side portions, corner portions continuous with both ends of each of the first straight side portions, and a pair of opposing second straight side portions. The second straight side portions are connected to the first straight side portions via their respective corner portions. When the length of the flange portion from the vertical wall portion to the outer periphery is defined as the flange width, the flange portion has a flange width W at at least one of the pair of first straight side portions and the pair of second straight side portions. Ｓ and at each corner portion, a flange width W Ｓ Flange width W is larger than Ｃ Flange width W Ｓis 3.3 times or less the thickness of the vertical wall portion.

[0011] The lid for a metal can according to the present disclosure can be applied to a can body having a small radius of curvature at the corner portion, and the lid for a metal can according to the present disclosure can improve the workability of joining the can body and the lid.

[0012] FIG. 1 is a perspective view showing a schematic configuration of a battery according to an embodiment. FIG. 2A is a schematic view illustrating a method for manufacturing a metal can according to an embodiment. FIG. 2B is a schematic view illustrating a method for manufacturing a metal can according to an embodiment. FIG. 2C is a schematic view illustrating a method for manufacturing a metal can according to an embodiment. FIG. 2D is a schematic view illustrating a method for manufacturing a metal can according to an embodiment. FIG. 2E is a schematic view illustrating a method for manufacturing a metal can according to an embodiment. FIG. 2F is a schematic view illustrating a method for manufacturing a metal can according to an embodiment. FIG. 3 is a plan view of a lid for a metal can according to a modified embodiment. FIG. 4 is a plan view of a lid according to another modified embodiment. FIG. 5 is a plan view of a lid according to yet another modified embodiment. FIG. 6 is a plan view of a lid according to yet another modified embodiment. FIG. 7 is a plan view of a lid according to yet another modified embodiment. FIG. 8 is a plan view of a lid according to yet another modified embodiment. FIG. 9 is a plan view of a lid according to yet another modified embodiment. FIG. 10 is a plan view of a lid according to yet another modified embodiment. FIG. 11 is a plan view of a lid according to yet another modified embodiment. FIG. 12 is a plan view of a lid according to yet another modification of the embodiment.

[0013] The lid for a metal can according to the embodiment comprises a bottom plate portion, a vertical wall portion, and a flange portion. The vertical wall portion is continuous with the peripheral edge of the bottom plate portion. The flange portion is continuous with the vertical wall portion on the opposite side of the bottom plate portion. The flange portion protrudes from the vertical wall portion toward the outer periphery of the vertical wall portion. The flange portion surrounds the bottom plate portion in a plan view of the lid. The outer periphery of the flange portion includes a pair of opposing first straight side portions, corner portions continuous with both ends of each of the first straight side portions, and a pair of opposing second straight side portions. The second straight side portions are connected to the first straight side portions via their respective corner portions. When the length of the flange portion from the vertical wall portion to the outer periphery is defined as the flange width, the flange portion has a flange width W at at least one of the pair of first straight side portions and the pair of second straight side portions. Ｓ and at each corner portion, a flange width W Ｓ Flange width W is larger than Ｃ Flange width W Ｓ is 3.3 times or less the plate thickness of the vertical wall portion (first configuration).

[0014] In the lid according to the first configuration, flanges are provided around the bottom plate and the vertical wall. Therefore, when joining the lid to, for example, a rectangular can body, the flanges can be placed on the end faces of the can body and welded. In this case, it is not necessary to closely contact the outer surfaces of the vertical wall portions of the lid with the inner surfaces of the can body along the entire periphery. Therefore, the shape of the vertical wall portions of the lid can be relaxed at the corners between the side walls of the can body.

[0015] More specifically, the flange portion of the lid has a flange width W at least at one of the first straight side portion and the second straight side portion of the outer periphery thereof, in other words, at a position corresponding to the flat side wall of the can body. Ｓ On the other hand, the flange portion has a flange width W at a position on the outer periphery that corresponds to a corner portion of the can body. Ｃ Flange width W Ｃ is the flange width W Ｓis larger than the radius of curvature of the can body corner. Therefore, when the flange portion of the lid is positioned on the end face of the can body, a relatively wide gap is formed between the inner surface of the can body and the vertical wall portion of the lid at the corner of the can body. Therefore, the shape and dimensions of the corner portion of the can body are less likely to affect the vertical wall portion of the lid at the position of the corner, allowing for relatively free design of the shape and dimensions of the vertical wall portion. For example, even if the radius of curvature of the corner of the can body is small, it is not necessary to form a corner portion of the vertical wall portion of the lid with a smaller diameter corresponding to the corner of the can body, and the vertical wall portion can be made to have a shape that is gentler than that of the can body at the position of the corner of the can body. In other words, the lid can have a shape that is easy to manufacture, for example, by drawing a metal sheet, without being limited by the radius of curvature of the corner of the can body. Therefore, the lid according to the first configuration can also be applied to can bodies with small radiuses of curvature of the corner portions.

[0016] In the lid according to the first configuration, the flange portion has a flange width W at a position corresponding to the flat side wall of the can body. Ｓ is configured to be 3.3 times or less the thickness of the vertical wall portion. This makes it easier to determine the position of the lid relative to the can body when the flange portion is placed on the end face of the can body during joining of the can body and the lid. More specifically, the flange width W Ｓ At this position, the vertical wall of the lid is in close proximity to or in contact with the side wall of the can body. Therefore, when the lid tries to slide against the end face of the can body, the flange width W Ｓ At this position, the vertical wall of the lid is likely to interfere with the side wall of the can body, and movement of the lid is likely to be restricted. This makes it easier to position the lid relative to the can body, improving the workability of joining the can body and the lid.

[0017] In the lid according to the first configuration, the flange width W Ｃ may be 3.3 times or more the thickness of the vertical wall portion (second configuration).

[0018] In the lid according to the second configuration, the flange portion has a flange width W at a position corresponding to the corner portion of the can body. Ｃ is configured to be 3.3 times or more the plate thickness of the vertical wall portion. However, the flange width W Ｃis the flange width W at a position corresponding to the flat side wall of the can body Ｓ This allows a wider gap to be secured between the inner surface of the can body and the vertical wall of the lid at the corner of the can body when the flange of the lid is placed on the end face of the can body. This allows for greater freedom in the shape of the vertical wall of the lid at the corner of the can body.

[0019] In the lid body according to the first or second configuration, the flange portion has a flange width W Ｓ (third configuration).

[0020] In the lid according to the third configuration, the flange portion has a flange width W that is 3.3 times or less the thickness of the vertical wall portion at positions corresponding to two or more of a pair of opposing first straight side portions and a pair of opposing second straight side portions of the outer periphery, in other words, two or more of the flat side walls of the can body. Ｓ In this case, when the can body and the lid body are joined together, even if the lid body tries to slide in multiple directions relative to the end face of the can body, each flange width W Ｓ At this position, the vertical wall of the lid can be brought into contact with the side wall of the can body, and movement of the lid can be more easily restricted. This makes it easier to position the lid relative to the can body, further improving the workability of joining the can body and the lid.

[0021] In the lid according to the third configuration, the flange portion has a flange width W Ｓ (fourth configuration).

[0022] In the lid according to the fourth configuration, the flange portion has a flange width W that is 3.3 times or less the plate thickness of the vertical wall portion at at least one first straight side portion and at least one second straight side portion of the outer peripheral edge. Ｓ That is, the flange portion has a flange width W at positions corresponding to two flat side walls of the can body that are arranged on either side of the corner portion. ＳIn this case, movement of the lid body in two directions intersecting each other can be restricted, which makes it easier to position the lid body relative to the can body.

[0023] The lid according to any one of the first to fourth configurations may be formed from a steel plate (fifth configuration).

[0024] Conventionally, in metal cans serving as battery exterior cans, aluminum alloy plates have been widely used as the material for the can body and lid. From the viewpoint of improving the energy density of batteries, it has been considered to thin the aluminum alloy plate. However, thinning the aluminum alloy plate raises concerns about a decrease in the rigidity of the can body and lid. On the other hand, the lid according to the fifth configuration is formed of steel plate, which has superior rigidity compared to aluminum alloy plate. Therefore, the lid can be made thinner compared to aluminum alloy plate while maintaining the rigidity of the lid.

[0025] In the cover according to the fifth configuration, the steel plate may be a surface-treated steel plate (sixth configuration).

[0026] In a typical battery outer can, when the can body and lid are formed from an aluminum alloy plate, the can body and lid are often welded together with the end face of the flat lid butting against the inner surface of the can body. If this joining structure is directly used with a steel can body and lid, the following problems may arise. For example, when a surface-treated steel plate is used for the lid to improve corrosion resistance, the end face of the lid is typically a cut end face that does not have a surface treatment layer such as a plating layer and exposes the base steel. However, in this joining structure, the end face of the lid is located inside the can body, which may cause corrosion due to contact with the contents, such as the electrolyte, in the can body. On the other hand, the lid according to the embodiment is joined to the can body with the flange portion placed on the end face of the can body. Therefore, the end face of the lid is located outside the can body. Therefore, even when the lid is formed from a surface-treated steel plate as in the sixth configuration, corrosion of the end face of the lid caused by the contents in the can body can be suppressed. This ensures the corrosion resistance of the lid.

[0027] A method for manufacturing a metal can according to an embodiment includes the steps of: preparing a lid according to any one of the first to sixth configurations; and a can body including a peripheral wall including a pair of first side walls and a pair of second side walls, and having an opening on at least one axial side of the peripheral wall; and arranging a flange portion on an end face of the peripheral wall so as to close the opening with the lid, and joining the peripheral wall and the flange portion. The pair of first side walls of the can body correspond to the pair of first straight side portions of the lid. The pair of second side walls of the can body correspond to the pair of second straight side portions of the lid. The second side walls are each connected to the first side walls via a corner portion (seventh configuration).

[0028] A metal can according to an embodiment includes a can body and a lid. The can body includes a peripheral wall. The peripheral wall includes a pair of first side walls and a pair of second side walls. The first side walls are arranged to face each other. The second side walls are arranged to face each other. The second side walls are each connected to the first side walls via a corner portion. The lid includes a bottom plate portion, a vertical wall portion, and a flange portion. The vertical wall portion is continuous with the peripheral edge of the bottom plate portion. The flange portion is continuous with the vertical wall portion on the opposite side of the bottom plate portion. The flange portion protrudes from the vertical wall portion toward the outer periphery of the vertical wall portion. The flange portion is arranged on an end face of the peripheral wall and is joined to the peripheral wall. The distance between the inner surface of the peripheral wall and the outer surface of the vertical wall portion at the corner portion is greater than the distance between the inner surface of the peripheral wall and the outer surface of the vertical wall portion at at least one of the pair of first side walls and the pair of second side walls (eighth configuration).

[0029] In the metal can according to the eighth configuration, the inner surface of the corner portion of the peripheral wall may have a radius of curvature of 3.0 mm or less (ninth configuration).

[0030] The battery according to this embodiment includes the metal can according to the eighth or ninth configuration as an outer can (tenth configuration).

[0031] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. In these drawings, the same or equivalent components are designated by the same reference numerals, and the same description will not be repeated.

[0032] 1 is a perspective view showing a schematic configuration of a battery 200 according to this embodiment. Although not particularly limited, the battery 200 is, for example, a lithium ion secondary battery. The battery 200 includes a metal can 100 as its outer can.

[0033] 1, the metal can 100 is a rectangular metal can. The metal can 100 includes a can body 10 and a lid 20.

[0034] In this embodiment, the can body 10 has a cylindrical shape with a bottom. The can body 10 includes a peripheral wall 11 and a bottom plate 12. The peripheral wall 11 has a substantially rectangular cylindrical shape. The bottom plate 12 is provided on one end side of the peripheral wall 11 in the axial direction of the can body 10. In this embodiment, the bottom plate 12 is formed integrally with the peripheral wall 11.

[0035] The lid body 20 is a separate member from the can body 10. The lid body 20 is disposed on the other end side of the peripheral wall 11 in the axial direction of the can body 10. That is, the lid body 20 is disposed so as to face the bottom plate 12 in the axial direction of the can body 10. The lid body 20 corresponds to the rectangular cylindrical peripheral wall 11 and has a substantially rectangular shape in a plan view.

[0036] The lid body 20 includes a bottom plate portion 21 , a vertical wall portion 22 , and a flange portion 23 .

[0037] The bottom plate portion 21 is a portion of the lid body 20 that is recessed toward the inside of the can body 10. The vertical wall portion 22 is a portion of the lid body 20 that rises from the bottom plate portion 21 toward the outside of the can body 10. The vertical wall portion 22 is continuous with the peripheral edge of the bottom plate portion 21. The vertical wall portion 22 is continuous around the entire circumference of the bottom plate portion 21 and has an annular shape.

[0038] The flange portion 23 is continuous with the vertical wall portion 22 on the opposite side of the bottom plate portion 21. The flange portion 23 protrudes from the vertical wall portion 22 toward its outer periphery. The flange portion 23 is connected to the bottom plate portion 21 by the vertical wall portion 22. The flange portion 23 surrounds the bottom plate portion 21 in a plan view of the lid body 20. A step is formed between the bottom plate portion 21 and the flange portion 23.

[0039] The flange portion 23 is disposed on an end surface of the peripheral wall 11 of the can body 10. The flange portion 23 is joined to the peripheral wall 11. Typically, the flange portion 23 is joined to the peripheral wall 11 by welding.

[0040] 2A to 2F, a method for manufacturing the metal can 100 will be described below. The method for manufacturing the metal can 100 according to this embodiment includes a preparation step and a joining step.

[0041] 2A, in the preparation step, the can body 10 and the lid body 20 are prepared. The configurations of the can body 10 and the lid body 20 prepared in this embodiment will be specifically described below.

[0042] In the can body 10, an internal space is defined by a peripheral wall 11 and a bottom plate 12. The can body 10 has an opening 13 on one side in the axial direction. The opening 13 is provided on the opposite side of the bottom plate 12.

[0043] In the can body 10 , the peripheral wall 11 includes a pair of first side walls 111 a and 111 b , a pair of second side walls 112 a and 112 b , and four corner portions 113 .

[0044] The first side walls 111a and 111b each have a substantially rectangular shape. The first side walls 111a and 111b are arranged to face each other. Corners 113 are provided continuously on both side edges of the first side wall 111a. Similarly, corners 113 are provided continuously on both side edges of the first side wall 111b.

[0045] The second side walls 112a, 112b each have a substantially rectangular shape. The second side walls 112a, 112b are arranged to face each other. The second side walls 112a, 112b face each other in a direction intersecting the facing direction of the first side walls 111a, 111b. In this embodiment, when viewed from the opening 13 side, the first side walls 111a, 111b face each other in the short direction of the can body 10, and the second side walls 112a, 112b face each other in the long direction of the can body 10.

[0046] The second side walls 112a and 112b are connected to the first side walls 111a and 111b, respectively, via corner portions 113. The second side wall 112a is connected to the first side wall 111a via one of the corner portions 113 and is connected to the first side wall 111b via the other corner portion 113. The second side wall 112b is connected to the first side wall 111a via one of the corner portions 113 and is connected to the first side wall 111b via the other corner portion 113 on the opposite side of the second side wall 112a from the first side walls 111a and 111b.

[0047] FIG. 2B is a plan view of the can body 10. FIG. 2B shows the can body 10 as viewed from the opening 13 side. As shown in FIG. 2B , in the can body 10, the outer surface of each corner portion 113 of the peripheral wall 11 can have a substantially arc-shaped configuration when viewed in a plan view of the can body 10 or in a cross section (transverse cross section) perpendicular to the extension direction of the corner portion 113. The inner surface of each corner portion 113 may have a substantially arc-shaped configuration or a pin-angle shape when viewed in a plan view or transverse cross section of the can body 10. The inner surface of each corner portion 113 has a radius of curvature R1. The radius of curvature R1 is preferably 3.0 mm or less. The radius of curvature R1 is more preferably 2.5 mm or less, and even more preferably 2.0 mm or less. The radius of curvature R1 is 0 mm or greater.

[0048] The radius of curvature R1 can be measured, for example, at a position 5.0 mm axially from the opening 13 of the can body 10. That is, in a cross section of the can body 10 cut perpendicularly to the axial direction at a position 5.0 mm axially from the opening 13, if the inner surface of each corner portion 113 has an arcuate shape, the radius of curvature R1 may be the radius of a circle passing through three points: both ends of each corner portion 113 and their midpoints. In this embodiment, if the inner surface of each corner portion 113 is formed in a pin-angle shape, the radius of curvature R1 is defined as 0 mm.

[0049] 2A , in the lid body 20 of this embodiment, the bottom plate portion 21 has a substantially rectangular shape in a plan view of the lid body 20. The vertical wall portion 22 corresponds to the bottom plate portion 21 and has a substantially quadrangular ring shape in a plan view of the lid body 20. Therefore, the vertical wall portion 22 includes a pair of first vertical wall portions 221 a, 221 b, a pair of second vertical wall portions 222 a, 222 b, and four corner portions 223.

[0050] The first vertical wall portions 221a, 221b face each other across the bottom plate portion 21. The second vertical wall portions 222a, 222b also face each other across the bottom plate portion 21. However, the second vertical wall portions 222a, 222b face each other in a direction intersecting the facing direction of the first vertical wall portions 221a, 221b. In the example of Fig. 2, the first vertical wall portions 221a, 221b face each other in the short direction of the lid body 20, and the second vertical wall portions 222a, 222b face each other in the long direction of the lid body 20.

[0051] One first vertical wall portion 221a has corner portions 223 formed continuously at both ends. The other first vertical wall portion 221b also has corner portions 223 formed continuously at both ends. The second vertical wall portion 222a is connected to the first vertical wall portion 221a via one of the corner portions 223 and is connected to the first vertical wall portion 221b via the other corner portion 223. The second vertical wall portion 222b is connected to the first vertical wall portion 221a via one of the corner portions 223 and is connected to the first vertical wall portion 221b via the other corner portion 223 on the opposite side of the second vertical wall portion 222a with respect to the first vertical walls 221a and 221b.

[0052] 2C is a plan view of the lid body 20. In this embodiment, four corner portions 223 are also provided on the vertical wall portion 22 of the lid body 20, corresponding to the four corner portions 113 (FIG. 2B) of the can body 10. Referring to FIG. 2C, the inner surface of each corner portion 223 can have a substantially arc shape when viewed in a plan view of the lid body 20 or in a cross section (transverse cross section) perpendicular to the height direction of the lid body 20. The inner surface of each corner portion 223 has a radius of curvature R2 ｉｎ It has.

[0053] Radius of curvature R2 ｉｎis larger than the radius of curvature R1 (FIG. 2B) of the inner surface of the corresponding corner portion 113 of the can body 10. When the maximum distance from one side to the other side in the short direction of the lid 20 in the annular vertical wall portion 22 is the width W, the radius of curvature R2 ｉｎ may be W / 2 or less. When the larger of the short-side length of the can body 10 (FIG. 2B) and the short-side length of the lid 20 is the overall width W0 of the metal can 100 (FIG. 1), the thickness of the peripheral wall 11 (FIG. 2B) of the can body 10 is t1, and the thickness of the vertical wall portion 22 of the lid 20 is t2, the width W of the vertical wall portion 22 is W0-2(t1+t2) or less. The width W of the vertical wall portion 22 may be {W0-2(t1+t2)}-2.0 [mm] or more. Although not particularly limited, the radius of curvature R2 ｉｎ is, for example, 3.0 mm or more. ｉｎ may be 5.0 mm or less.

[0054] 2C , in the cover 20, the outer peripheral edge 24 of the flange portion 23 has a substantially rectangular shape. The outer peripheral edge 24 includes a pair of first straight sides 241 a, 241 b, a pair of second straight sides 242 a, 242 b, and four corners 243.

[0055] The first straight edge portions 241a, 241b correspond to the first side walls 111a, 111b ( FIG. 2B ) of the can body 10. That is, in a metal can 100 ( FIG. 1 ) manufactured using the can body 10 and the lid 20, the first straight edge portion 241a is disposed on the first side wall 111a side of the can body 10, and the first straight edge portion 241b is disposed on the other first side wall 111b side of the can body 10. The first straight edge portions 241a, 241b are opposing sides of the outer circumferential edge 24. The first straight edge portions 241a, 241b each have a substantially linear shape in a plan view of the lid 20. The corner portions 243 are continuous with both ends of each of the first straight edge portions 241a, 241b.

[0056] The second straight side portions 242a, 242b correspond to the second side walls 112a, 112b ( FIG. 2B ) of the can body 10. That is, in a metal can 100 ( FIG. 1 ) manufactured using the can body 10 and the lid 20, the second straight side portion 242a is disposed on the side of one second side wall 112a of the can body 10, and the second straight side portion 242b is disposed on the side of the other second side wall 112b of the can body 10. The second straight side portions 242a, 242b are opposing sides of the outer circumferential edge 24. The second straight side portions 242a, 242b each have a substantially linear shape in a plan view of the lid 20. The second straight side portions 242a, 242b are connected to the first straight side portions 241a, 241b via corner portions 243, respectively. The second straight side portion 242a is connected to the first straight side portion 241a via one of the corner portions 243, and is connected to the first straight side portion 241b via the other corner portion 243. The second side wall 112b is connected to the first straight side portion 241a via one of the corner portions 243, and is connected to the first straight side portion 241b via the other corner portion 243, on the opposite side of the second straight side portion 242a with respect to the first straight side portions 241a and 241b.

[0057] Each corner portion 243 may have a substantially arc shape in a plan view of the lid body 20, or may be formed in a pin-angle shape. ｏｕｔ At each corner 243 of the flange 23, the radius of curvature R2 ｏｕｔ is the radius of curvature R2 of the inner surface of the corner portion 223 of the vertical wall portion 22 ｉｎ Radius of curvature R2 is smaller than ｏｕｔ When each corner portion 243 has a substantially arcuate shape, the radius of curvature R2 ｏｕｔ When each corner portion 243 is formed in a pin-angle shape, the radius of curvature R2 ｏｕｔ is defined as 0 mm. Radius of curvature R2 ｏｕｔ is R2 ｉｎ Although not particularly limited, the radius of curvature R2 ｏｕｔ is, for example, 3.0 mm or less. ｏｕｔ is preferably approximately the same as the radius of curvature of the outer surface of each corner portion 113 (FIG. 2B) of the peripheral wall 11 of the can body 10.

[0058] The can body 10 and the lid 20 are both formed from metal plates. In this embodiment, the bottomed, cylindrical can body 10 is formed, for example, by deep drawing a metal plate (blank). The can body 10 may also be formed, for example, by drawing a metal plate multiple times (multi-stage drawing).

[0059] The lid body 20 is formed by drawing a metal plate (blank). The lid body 20 may be obtained by drawing alone, or may be obtained by, for example, a restriking process and / or a trimming process after drawing. In the restriking process, for example, the diameters of the corners between the bottom plate portion 21 and the vertical wall portion 22 and the corners between the vertical wall portion 22 and the flange portion 23 are reduced. In the trimming process, unnecessary portions of the outer periphery of the molded product after drawing are cut off.

[0060] Steel sheets can be used as the metal sheets for the can body 10 and the lid body 20. That is, the can body 10 and the lid body 20 may each be formed of a steel sheet. The steel sheet may be a stainless steel sheet or a surface-treated steel sheet. The surface-treated steel sheet includes a plated steel sheet. When the manufactured metal can 100 is an outer can for the battery 200 as in this embodiment ( FIG. 1 ), the surface-treated steel sheet for the can body 10 and the lid body 20 is preferably a nickel-plated steel sheet. Alternatively, when the metal can 100 is an outer can for the battery 200, the steel sheet for the can body 10 and the lid body 20 is preferably a stainless steel sheet. However, the can body 10 and the lid body 20 may be formed of a metal sheet other than a steel sheet. The can body 10 and the lid body 20 may be formed of a metal sheet made of aluminum, titanium, copper, or an alloy thereof.

[0061] (Joining Process) Returning to FIG. 2A , in the joining process, the flange portion 23 of the lid body 20 is placed on the end face of the peripheral wall 11 of the can body 10 so that the lid body 20 closes the opening 13 of the can body 10. Then, the peripheral wall 11 of the can body 10 and the flange portion 23 of the lid body 20 are joined together. The flange portion 23 of the lid body 20 is joined to the peripheral wall 11 of the can body 10 around its entire periphery by, for example, continuous welding. The continuous welding is typically laser welding. The continuous welding may be, for example, arc welding or electron beam welding. The lid body 20 is fixed to the can body 10 after the necessary contents have been placed in the internal space of the can body 10. When the metal can 100 to be manufactured is an exterior can for a battery 200 ( FIG. 1 ), electrodes, an electrolyte, etc. are placed inside the can body 10.

[0062] 2D, 2E, and 2F are diagrams showing the can body 10 and the lid 20 before joining. FIGS. 2D, 2E, and 2F show a state in which the lid 20 is placed on the end face of the can body 10 on the opening 13 side. FIG. 2D is a cross-sectional view (IID-IID cross-sectional view of FIG. 2A ) of the can body 10 and the lid 20 cut along the thickness direction at the first straight edge 241a or 241b of the outer peripheral edge 24 of the lid 20. FIG. 2E is a cross-sectional view (IIE-IIE cross-sectional view of FIG. 2A ) of the can body 10 and the lid 20 cut along the thickness direction at the second straight edge 242a or 242b of the outer peripheral edge 24 of the lid 20. FIG. 2F is a cross-sectional view (IIF-IIF cross-sectional view of FIG. 2A) of the can body 10 and the lid 20 cut in the thickness direction at the position of a corner portion 243 of the outer peripheral edge 24 of the lid 20.

[0063] In the lid 20 according to this embodiment, the first straight side portions 241a, 241b have the same configuration, and the second straight side portions 242a, 242b have the same configuration. Therefore, in the following description, unless a particular distinction is required, the first straight side portions 241a, 241b will be collectively referred to as the first straight side portion 241, and the second straight side portions 242a, 242b will be collectively referred to as the second straight side portion 242. Similarly, with regard to the can body 10, unless a particular distinction is required, the first side walls 111a, 111b of the peripheral wall 11 will be collectively referred to as the first side wall 111, and the second side walls 112a, 112b will be collectively referred to as the second side wall 112.

[0064] 2D , when the can body 10 and the lid body 20 are viewed in a cross section (longitudinal cross section) along the plate thickness direction, the vertical wall portion 22 of the lid body 20 includes a flat portion 224 and ridge portions 225 and 226. The flat portion 224 has a substantially straight shape in the vertical cross section of the lid body 20. The flat portion 224 may be parallel to the peripheral wall 11 of the can body 10 in the vertical cross section of the can body 10 and the lid body 20, or may be slightly inclined relative to the peripheral wall 11. In the lid body 20, the flat portion 224 of the vertical wall portion 22 is connected to the bottom plate portion 21 via the ridge portion 225. The flat portion 224 is connected to the flange portion 23 via the ridge portion 226. The ridge portions 225 and 226 may have a substantially arc shape in the vertical cross section of the lid body 20. That is, the flat portion 224 may be smoothly connected to the bottom plate portion 21 and the flange portion 23 by the ridge portions 225 and 226, respectively.

[0065] Although not particularly limited, the length of flat portion 224 is, for example, 0.1 mm or more, and preferably 0.2 mm or more. The length of flat portion 224 is, for example, the length from the end of the rounded edge of ridge line portion 225 on the flat portion 224 side to the end of the rounded edge of ridge line portion 226 on the flat portion 224 side, and can be measured along the outer surface of flat portion 224 (the surface facing can body 10) in a vertical cross-sectional view of lid 20. The length of flat portion 224 may be 2.0 mm or less.

[0066] When the length of the flange portion 23 from the vertical wall portion 22 to the outer peripheral edge (end surface) 24 of the lid body 20 is defined as the flange width, the flange portion 23 has a flange width W Ｓ Flange width W Ｓ is the distance along the surface of the flange portion 23 from the flat portion 224 of the vertical wall portion 22 to the first straight side portion 241 in the vertical cross section of the lid body 20. For example, in the vertical cross section of the lid body 20, the flange width W is the linear distance along the underside of the flange portion 23 from the boundary between the flat portion 224 and the ridge portion 226 on the outer surface of the vertical wall portion 22, in other words, the R end of the ridge portion 226 on the outer surface of the vertical wall portion 22 on the flat portion 224 side, to the first straight side portion 241. Ｓ It can be said that:

[0067] Flange width W Ｓ satisfies the following formula (1): Ｓ≦3.3×t2 (1)

[0068] Flange width W Ｓ Is W Ｓ It is more preferable that the flange width W satisfies ≦3.0×t2. Ｓ , 0.8 × t2 ≦ W Ｓ may be satisfied.

[0069] Before the lid 20 is joined to the can body 10, the flange portion 23 of the lid 20 is placed on the end face of the peripheral wall 11. At this time, at the position of the first straight side portion 241 of the lid 20, the flat portion 224 of the vertical wall portion 22 faces the flat first side wall 111 of the peripheral wall 11 of the can body 10. The vertical wall portion 22 of the lid 20 may face the first side wall 111 of the can body 10 with a gap therebetween, or may come into contact with the first side wall 111.

[0070] The distance L between the inner surface of the peripheral wall 11 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid body 20 in the first side wall 111 Ｓ The distance L is 1.0 mm or less. Ｓ The distance L may be 0 mm or more, but may also be 0.3 mm or more. Ｓ is the shortest distance in a direction perpendicular to the axial direction from the flat portion 224 of the vertical wall portion 22 of the lid 20 to the first side wall 111 of the can body 10 in a vertical cross-sectional view of the can body 10 and the lid 20.

[0071] 2E, in this embodiment, the flange portion 23 of the lid body 20 has a flange width W Ｓ Flange width W Ｓ is the distance along the surface of the flange portion 23 from the flat portion 224 of the vertical wall portion 22 to the second straight side portion 242 in the vertical cross section of the lid body 20. For example, in the vertical cross section of the lid body 20, the flange width W is the linear distance along the underside of the flange portion 23 from the boundary between the flat portion 224 and the ridge portion 226 on the outer surface of the vertical wall portion 22, in other words, the R end of the ridge portion 226 on the outer surface of the vertical wall portion 22 on the flat portion 224 side, to the second straight side portion 242. Ｓ The flange width W at the position of the second straight side portion 242 can be expressed as follows: Ｓ is the flange width W at the position of the first straight side portion 241 Ｓ(FIG. 2D). However, the flange width W at the position of the second straight side portion 242 can be set in the same range. Ｓ is the flange width W at the position of the first straight side portion 241 Ｓ It may be equal to or different from.

[0072] At the position of the second straight edge portion 242 of the lid body 20, the flat portion 224 of the vertical wall portion 22 faces the flat second side wall 112 of the peripheral wall 11 of the can body 10. The vertical wall portion 22 of the lid body 20 may face the second side wall 112 of the can body 10 with a gap therebetween, or may be in contact with the second side wall 112.

[0073] The distance L between the inner surface of the peripheral wall 11 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid body 20 in the second side wall 112 Ｓ The distance L is 1.0 mm or less. Ｓ The distance L may be 0 mm or more, but may also be 0.3 mm or more. Ｓ is the shortest distance in a direction perpendicular to the axial direction from the flat portion 224 of the vertical wall portion 22 of the lid 20 to the second side wall 112 of the can body 10 in a vertical cross-sectional view of the can body 10 and the lid 20. Ｓ is the distance L at the first side wall 111 Ｓ (FIG. 2D) may be equal to or different from the

[0074] As shown in Figures 2D and 2E, the thickness t2 of the lid body 20 can be measured at the flat portion 224 of the vertical wall portion 22 at the position of the straight side portion 241 or 242. The thickness t2 is, for example, 0.3 mm or more. The thickness t2 may be 2.0 mm or less. In this embodiment, the thickness t2 of the lid body 20 is greater than the thickness t1 of the can body 10. However, the thickness t2 of the lid body 20 may be less than the thickness t1 of the can body 10. The thickness t1 of the can body 10 is the thickness of the side wall 111 or 112. The thickness t1 can be measured at a position on the side wall 111 or 112 facing the flat portion 224 of the vertical wall portion 22 of the lid body 20.

[0075] 2F shows a cross section of the can body 10 and the lid 20 at a position midway between the corner portion 243, i.e., at a position 45° from each of the boundaries between the first straight side portion 241 and the corner portion 243 and the second straight side portion 242 and the corner portion 243. As shown in FIG. 2F, the flange portion 23 of the lid 20 has a flange width W Ｃ Flange width W Ｃ is the distance along the surface of the flange 23 from the flat portion 224 of the vertical wall 22 to the corner portion 243 in the vertical cross section of the lid 20. For example, in the vertical cross section of the lid 20, the flange width W is the linear distance along the underside of the flange 23 from the boundary between the flat portion 224 and the ridge portion 226, in other words, the R end of the ridge portion 226 on the flat portion 224 side, to the corner portion 243. Ｃ It can be said that:

[0076] Flange width W at the position of the corner portion 243 Ｃ is the flange width W at the position of the first straight side portion 241 Ｓ (FIG. 2D), and the flange width W Ｓ (Fig. 2E) Flange width W Ｃ and flange width W Ｓ The difference between the flange width W and the flange width W is, for example, 1.5 mm or more, and preferably 2.0 mm or more. Ｃ can satisfy the following formula (2): 3.3×t2≦W Ｃ　 (2)

[0077] Flange width W Ｃ 3.5 × t2 ≦ W Ｃ It is more preferable that the flange width W Ｃ Is W Ｃ ≦√2(W0 / 2) may be satisfied.

[0078] At the position of the corner portion 243 of the lid body 20, the flat portion 224 of the vertical wall portion 22 faces the corner portion 113 between the side walls 111 and 112 (FIGS. 2D and 2E) of the peripheral wall 11 of the can body 10. The vertical wall portion 22 of the lid body 20 faces the corner portion 113 of the can body 10 with a gap therebetween.

[0079] The distance L between the inner surface of the peripheral wall 11 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid body 20 at the corner portion 113 Ｃ The distance L is, for example, 0.5 mm or more, and preferably 1.0 mm or more. Ｃ The distance L may be, for example, 30.0 mm or less. Ｃ is the shortest distance in a direction perpendicular to the axial direction from the outer surface of the flat portion 224 of the vertical wall portion 22 of the lid body 20 to the inner surface of the corner portion 113 of the can body 10 in a vertical cross-sectional view of the can body 10 and the lid body 20.

[0080] distance L Ｃ is the distance L between the inner surface of the peripheral wall 11 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid body 20 at the first side wall 111. Ｓ (Fig. 2D). Ｃ is the distance L between the inner surface of the peripheral wall 11 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid body 20 at the second side wall 112. Ｓ The distance L at the position of the corner portion 113 is larger than that in FIG. Ｃ and the distances L at the positions of the side walls 111 and 112. Ｓ The difference is, for example, 0.5 mm or more, and preferably 1.5 mm or more.

[0081] As described above, the lid 20 is placed on the end face of the peripheral wall 11 so as to close the opening 13 of the can body 10, and then joined to the peripheral wall 11 by welding. At this time, the outer peripheral edge (end face) 24 of the flange portion 23 of the lid 20 may be flush with the outer surface of the peripheral wall 11, or may be located on the outer peripheral side or inner peripheral side of the outer surface of the peripheral wall 11. Even after the lid 20 is joined to the peripheral wall 11 of the can body 10, the distance L Ｃ and distance L Ｓ That is, even after the lid 20 and the can body 10 are joined to form the metal can 100 (FIG. 1), the distance L between the inner surface of the peripheral wall 11 at the corner portion 113 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid 20 remains constant. Ｃ is the distance L between the inner surface of the peripheral wall 11 and the outer surface of the vertical wall portion 22 in each of the first side wall 111 and the second side wall 112. Ｓ In the manufactured metal can 100, the distance L Ｃ and distance L ＳThe difference is, for example, 0.5 mm or more, and preferably 1.5 mm or more.

[0082] [Effect] In the metal can 100 according to this embodiment, the flange portion 23 of the lid 20 is disposed on and joined to the end face of the peripheral wall 11 of the can body 10. In other words, when fixing the lid 20 to the can body 10, the flange portion 23 is joined to the peripheral wall 11, and it is not necessary to bring the vertical wall portion 22 into close contact with the peripheral wall 11 over the entire periphery. Therefore, the shape of the vertical wall portion 22 of the lid 20 can be relaxed at the positions of the corner portions 113 of the peripheral wall 11 of the can body 10.

[0083] More specifically, in the lid 20 according to this embodiment, the flange portion 23 has a flange width W Ｓ and the flange width W Ｃ Flange width W Ｃ is the flange width W Ｓ Therefore, when the flange portion 23 is disposed on the end face of the peripheral wall 11, the distance L between the vertical wall portion 22 and the peripheral wall 11 at the position of the corner portion 243 of the lid body 20 and the corresponding corner portion 113 of the can body 10 is larger than Ｃ In this case, the shape and dimensions of the vertical wall portion 22 of the lid body 20 can be set relatively freely without being affected by the shape and dimensions of the corner portion 113 of the can body 10. For example, even if the radius of curvature R1 of the inner surface of the corner portion 113 of the can body 10 is relatively small, it is not necessary to reduce the diameter of the corner portion 223 in the vertical wall portion 22 of the lid body 20, and the radius of curvature R2 of the corner portion 223 can be set relatively freely. ｉｎ The radius of curvature R1 of the corner portion 113 can be made larger than the radius of curvature R1. Therefore, the lid body 20 can be easily formed by, for example, drawing a metal plate. Therefore, the lid body 20 according to this embodiment can be applied to a can body 10 in which the radius of curvature R1 of the corner portion 113 is small.

[0084] In the lid body 20 according to this embodiment, the flange width W at the positions of the straight side portions 241 and 242 Ｓis 3.3 times or less the thickness t2 of the vertical wall portion 22, and preferably 3.0 times or less the thickness t2. This makes it easier to determine the position of the lid 20 relative to the can body 10 when joining the can body 10 and the lid 20. Specifically, the flange width W Ｓ By setting the distance L between the vertical wall portion 22 and the peripheral wall 11 at the positions of the straight side portions 241, 242 of the lid 20 and the corresponding positions of the side walls 111, 112 of the can body 10, when the flange portion 23 of the lid 20 is placed on the end face of the peripheral wall 11 of the can body 10, Ｓ The distance L becomes smaller. Ｓ is, for example, 1.0 mm or less. In this case, when the lid body 20 moves in the short-side direction or the long-side direction relative to the can body 10, the vertical wall portion 22 is likely to interfere with the side wall 111 or 112 before the lid body 20 significantly shifts out of position from the can body 10, and the movement of the lid body 20 is likely to be restricted. For example, the flat portion 224 of the vertical wall portion 22 abuts against the side wall 111 or 112, which can prevent the lid body 20 from shifting out of position relative to the can body 10. Therefore, it is easy to position the lid body 20 relative to the can body 10, and the workability of joining the can body 10 and the lid body 20 can be improved.

[0085] In the lid body 20 according to this embodiment, the flange width W at the position of the corner portion 243 Ｃ is preferably 3.3 times or more the thickness t2 of the vertical wall portion 22, and more preferably 3.5 times or more the thickness t2. As a result, when the flange portion 23 is disposed on the end face of the peripheral wall 11, a large distance L is formed between the vertical wall portion 22 and the peripheral wall 11 at the positions of the corner portion 243 of the lid body 20 and the corresponding corner portion 113 of the can body 10. Ｃ Therefore, the degree of freedom in the shape of the vertical wall portion 22 of the lid body 20 at the position of the corner portion 113 can be increased.

[0086] The lid 20 according to this embodiment has a relatively small flange width W ＳIn this case, when the lid body 20 attempts to move in the short direction relative to the can body 10, the vertical wall portion 22 of the lid body 20 can be made to interfere with the first side wall 111 of the can body 10 at the first straight edge portion 241 side. On the other hand, when the lid body 20 attempts to move in the long direction relative to the can body 10, the vertical wall portion 22 of the lid body 20 can be made to interfere with the second side wall 112 of the can body 10 at the second straight edge portion 242 side. Therefore, movement of the lid body 20 in both the long direction and the short direction can be restricted. This makes it easier to position the lid body 20 relative to the can body 10, and further improves the workability of joining the can body 10 and the lid body 20.

[0087] In this embodiment, the can body 10 and the lid body 20 are preferably formed from steel plate. Steel plate has higher rigidity than aluminum alloy plate, etc. Therefore, by forming the can body 10 and the lid body 20 from steel plate, the can body 10 and the lid body 20 can be made thinner while ensuring the rigidity of the can body 10 and the lid body 20. As a result, when batteries 200 each having a metal can 100 as an exterior can are arranged in an electric vehicle, for example, the proportion of the metal can 100 in the mounting space for the batteries 200 is smaller than when an exterior can made of a general aluminum alloy plate is used. Therefore, the space efficiency and energy density of the battery 200 can be improved.

[0088] In this embodiment, the lid 20 may be formed of a surface-treated steel plate from the viewpoint of improving corrosion resistance. In this embodiment, when the lid 20 is joined to the can body 10 to form the metal can 100, the end face of the lid 20, i.e., the outer periphery 24 of the flange portion 23, is disposed outside the can body 10. This makes it possible to suppress corrosion of the end face of the lid 20 caused by the contents in the can body 10. This therefore ensures good corrosion resistance for the lid 20.

[0089] In this embodiment, the peripheral wall 11 of the can body 10 has a radius of curvature R1 on the inner surface of the corner portion 113. The radius of curvature R1 may be 3.0 mm or less. By reducing the diameter of the corner portion 113 in this manner, it is possible to arrange batteries 200 using the metal can 100 as an exterior can relatively closely together, for example, in an electric vehicle. This allows the energy density of the batteries 200 to be increased in the electric vehicle or the like.

[0090] However, the use of the metal can 100 is not limited to the exterior can of the vehicle-mounted battery 200. The metal can 100 may also be used as an exterior can of a stationary battery. The metal can 100 may also be used for purposes other than the exterior can of a battery.

[0091] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit of the present disclosure.

[0092] In the above embodiment, the bottom plate portion 21 and the vertical wall portion 22 of the lid body 20 have a substantially rectangular shape in a plan view of the lid body 20. However, the shapes of the bottom plate portion 21 and the vertical wall portion 22 are not limited to this.

[0093] For example, as shown in Figures 3 and 4, the bottom plate portion 21 and the vertical wall portion 22 may have a polygonal shape in a plan view of the lid body 20. In the above embodiment, the vertical wall portion 22 has a substantially arc shape at each corner portion 243 of the outer peripheral edge 24 of the lid body 20 in a plan view of the lid body 20. On the other hand, in the example of Figure 3, the vertical wall portion 22 has a C-chamfered shape at each corner portion 243 of the outer peripheral edge 24 of the lid body 20 in a plan view of the lid body 20. That is, at each corner portion 243 of the outer peripheral edge 24, the vertical wall portion 22 has a linear shape in a plan view of the lid body 20 and is inclined with respect to the first straight side portion 241. In the example of Figure 4, the bottom plate portion 21 and the vertical wall portion 22 have a cross shape in a plan view of the lid body 20.

[0094] In the above embodiment and the example of Figures 3 and 4, the vertical wall portion 22 extends substantially parallel to the outer peripheral edge 24 in the plan view of the lid body 20 at the positions of the straight side portions 241 and 242. However, as shown in Figures 5 and 6, the vertical wall portion 22 does not have to extend parallel to the outer peripheral edge 24 in the plan view of the lid body 20 at the positions of the first straight side portion 241 and / or the second straight side portion 242. The bottom plate portion 21 and the vertical wall portion 22 may have, for example, an elliptical shape as shown in Figure 5 or a cloud shape as shown in Figure 6 in the plan view of the lid body 20. In this case, the flange width W Ｓ is the minimum value of the flange width at the straight side portions 241 and 242.

[0095] In the examples shown in FIGS. 3 to 6, the flange widths W at the positions of the first straight side portion 241 and the second straight side portion 242 of the lid body 20 are Ｓ is the flange width W at the position of each corner portion 243 Ｃ and is 3.3 times or less the thickness t2 of the vertical wall portion 22. Therefore, when the lid body 20 is attached to the can body 10, the distance L between the inner surface of each corner portion 113 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid body 20 is Ｃ (FIG. 2F) is the distance L between the inner surfaces of the side walls 111 and 112 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid body 20. Ｓ 2D and 2E. Therefore, similarly to the above embodiment, the corner portion 113 of the can body 10 can be made smaller in diameter, while the molding flexibility of the lid body 20 can be ensured.

[0096] 7 to 12, the bottom plate portion 21 and the vertical wall portion 22 may be divided into a plurality of portions in the lid body 20. Even in this case, the flange width W of at least one of the first straight side portion 241 and the second straight side portion 242 in the lid body 20 is Ｓ is the flange width W at the position of each corner portion 243 Ｃ and 3.3 times or less the thickness t2 of the vertical wall portion 22. Thus, when the lid body 20 is attached to the can body 10, the distance L between the inner surface of each corner portion 113 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid body 20 is Ｃ (FIG. 2F) is a distance L between the inner surface of at least one of the side walls 111, 112 of the can body 10 and the outer surface of the vertical wall portion 22 of the lid body 20.Ｓ 2D and 2E. Therefore, similarly to the above embodiment, the corner portion 113 of the can body 10 can be made smaller in diameter, while ensuring flexibility in molding the lid 20.

[0097] In the lid body 20 in the above embodiment and the examples in FIGS. 3 to 12, the vertical wall portion 22 is present at the position of each corner portion 243. In other words, when the lid body 20 is cut in the thickness direction at the exact midpoint of the corner portion 243, the vertical wall portion 22 is present on the cut surface. However, the vertical wall portion 22 does not necessarily have to be present at the position of each corner portion 243. In this case, the flange width W at each corner portion 243 is Ｃ is the length from the corner portion 243 to the first straight side portion 241 in a plan view of the lid 20, and can be assumed to be the length along a straight line at 45° from each of the boundary between the first straight side portion 241 and the corner portion 243 and the boundary between the second straight side portion 242 and the corner portion 243. Therefore, a relatively small flange width W Ｓ If there is a part like this, Ｃ >W Ｓ In addition, when the lid 20 is attached to the can body 10, the distance L Ｃ can be assumed to be the distance from the inner surface of each corner portion 113 of the can body 10 to the side wall 111. Therefore, a relatively small distance L Ｓ (Fig. 2D and Fig. 2E), Ｃ >L Ｓ It can be said that the following is satisfied.

[0098] 3 to 12, the lid 20 has a rectangular shape in a plan view. That is, at the outer peripheral edge 24 of the flange portion 23, the first straight side portion 241 is longer than the second straight side portion 242. However, the lid 20 may have a square shape in a plan view. That is, at the outer peripheral edge 24 of the flange portion 23, the length of the first straight side portion 241 and the length of the second straight side portion 242 may be substantially equal.

[0099] In the above embodiment, the can body 10 has a cylindrical shape with a bottom. That is, the can body 10 has an opening 13 on one axial side and a bottom plate 12 on the other axial side. However, the can body 10 may have a cylindrical shape without a bottom. In this case, the can body 10 has openings 13 on both axial sides. The lids 20 may be arranged on both axial sides of the can body 10 so as to close both openings 13 of the can body 10. The flange portions 23 of each lid 20 are arranged on the end faces of the cylindrical peripheral wall 11 and are joined to the peripheral wall 11.

[0100] When the can body 10 has a bottomless cylindrical shape, the can body 10 may be formed, for example, by bending a metal plate (blank) multiple times and then welding the ends of the metal plate together. Alternatively, the can body 10 may be formed by correcting a circular tube into a rectangular tube shape.

[0101] 100: Metal can 10: Can body 11: Peripheral wall 111, 111a, 111b: First side wall 112, 112a, 112b: Second side wall 113: Corner portion 13: Opening 20: Lid 21: Bottom plate portion 22: Vertical wall portion 23: Flange portion 24: Outer periphery 241, 241a, 241b: First straight side portion 242, 242a, 242b: Second straight side portion 243: Corner portion 200: Battery

Claims

A lid for a metal can, A bottom plate portion; a vertical wall portion continuous with the periphery of the bottom plate portion; a flange portion that is continuous with the vertical wall portion on the opposite side of the bottom plate portion, protrudes from the vertical wall portion toward the outer periphery of the vertical wall portion, and surrounds the bottom plate portion in a plan view of the lid body; Equipped with the outer peripheral edge of the flange portion includes a pair of opposing first straight side portions, corner portions continuous with both ends of each of the first straight side portions, and a pair of opposing second straight side portions, the second straight side portions being connected to the first straight side portions via the corner portions, When the length of the flange portion from the vertical wall portion to the outer circumferential edge is defined as a flange width, the flange portion has a flange width W Ｓ and the flange width W Ｓ Flange width W is larger than Ｃ and The flange width W Ｓ is 3.3 times or less the thickness of the vertical wall portion. 　 The lid according to claim 1, The flange width W Ｃ is 3.3 times or more the thickness of the vertical wall portion. 　 The lid according to claim 1, The flange portion has a flange width W Ｓ A lid body having 　 The lid according to claim 3, The flange portion has a flange width W Ｓ A lid body having 　 The lid according to claim 1, The lid body is formed of a steel plate. 　 The lid according to claim 5, The lid body, wherein the steel plate is a surface-treated steel plate. 　 A method for manufacturing a metal can, comprising: a process for preparing the lid according to any one of claims 1 to 6, and a can body including a peripheral wall including a pair of first side walls corresponding to the pair of first straight side portions and a pair of second side walls corresponding to the pair of second straight side portions and connected to the first side walls via corner portions, and the can body has an opening on at least one side in an axial direction; a step of placing the flange portion on the end surface of the peripheral wall so as to close the opening with the lid body, and joining the peripheral wall and the flange portion; A manufacturing method comprising: 　 A metal can, a can body including a peripheral wall including a pair of first side walls arranged to face each other and a pair of second side walls arranged to face each other and connected to the first side walls via corner portions; a cover body including a bottom plate portion, a vertical wall portion continuous with the peripheral edge of the bottom plate portion, and a flange portion continuous with the vertical wall portion on the opposite side of the bottom plate portion and protruding from the vertical wall portion toward the outer periphery of the vertical wall portion, the flange portion being disposed on an end face of the peripheral wall and joined to the peripheral wall; Equipped with a distance between the inner surface of the peripheral wall and the outer surface of the vertical wall portion at the corner portion is greater than a distance between the inner surface of the peripheral wall and the outer surface of the vertical wall portion at at least one of the pair of first side walls and the pair of second side walls. 　 The metal can according to claim 8, A metal can, wherein the inner surface of the corner portion of the peripheral wall has a radius of curvature of 3.0 mm or less. 　 A battery, A battery comprising the metal can according to claim 8 or 9 as an outer can.

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