Molding device and molding method, and pouch-shaped battery case molded thereby

Abstract

A forming device according to an embodiment of the present invention can form a cup portion in a pouch film. The forming device may include a die having a first opening, a stripper that fixes the pouch film above the die and has a second opening formed at a position corresponding to the first opening, an upper punch that presses the pouch film through the second opening, and a lower punch that presses the pouch film between an outer periphery of the upper punch and an inner periphery of the second opening through the first opening.

Description

[Technical Field]

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0140761, filed October 27, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a molding device and molding method for molding a pouch film, and to a pouch-type battery case molded thereby. [Background technology]

[0003] Generally, types of secondary batteries include nickel-cadmium batteries, nickel-metal hydride batteries, lithium-ion batteries, lithium-ion polymer batteries, etc. These secondary batteries are used not only in small products such as digital cameras, DVD players, MP3 players, mobile phones, PDAs, portable game devices, power tools, and e-bikes, but also in large products that require high output such as electric vehicles and hybrid vehicles, as well as in power storage devices and backup power storage devices that store surplus generated power and new renewable energy.

[0004] To manufacture such a secondary battery, first, an electrode active material slurry is applied to a positive electrode current collector and a negative electrode current collector to form a positive electrode and a negative electrode, which are then stacked on both sides of a separator to form an electrode assembly of a predetermined shape, and then the electrode assembly is placed in a battery case, an electrolyte is injected, and the battery case is sealed.

[0005] Secondary batteries are classified into pouch types and can types depending on the material of the case that houses the electrode assembly. Pouch types house the electrode assembly in a pouch made of flexible polymer material, while can types house the electrode assembly in a case made of metal or plastic.

[0006] Generally, a pouch-type battery case is manufactured by pressing a flexible pouch film to form a cup portion, and then, after the cup portion is formed, an electrode assembly is placed inside the cup portion and the sides are sealed to manufacture a secondary battery.

[0007] Generally, in such press working, drawing is performed by inserting a pouch film between a die and a stripper, and applying pressure to the pouch film with a punch to stretch the pouch film.

[0008] However, in such a conventional method, if the cup portion is formed too deep, cracks may occur in the pouch film, and there is a limit to how deep the cup portion can be increased. Summary of the Invention [Problem to be solved by the invention]

[0009] One problem to be solved by the present invention is to provide a molding device and a molding method that can form a deep cup portion in a pouch film by performing the molding process in multiple steps.

[0010] Another object of the present invention is to provide a pouch-shaped battery case manufactured by the molding apparatus or the molding method. [Means for solving the problem]

[0011] A forming device according to an embodiment of the present invention can form a cup portion in a pouch film. The forming device may include a die having a first opening, a stripper that fixes the pouch film above the die and has a second opening formed at a position corresponding to the first opening, an upper punch that presses the pouch film through the second opening, and a lower punch that presses the pouch film between an outer periphery of the upper punch and an inner periphery of the second opening through the first opening.

[0012] The lower punch may apply a first pressure to the pouch film while the upper punch is positioned at the second opening, and the upper punch may apply a second pressure to the pouch film while the lower punch is separated from the first opening.

[0013] The upper punch may press the pouch film to a depth at which the upper punch protrudes downward from the first opening.

[0014] The upper surface of the lower punch may be formed in a bulging state.

[0015] A forming method according to an embodiment of the present invention can form a cup portion in a pouch film. The forming method may include a fixing step of fixing the pouch film between a die having a first opening and a stripper having a second opening, a primary pressurizing step of a lower punch applying primary pressure to the pouch film between an outer periphery of an upper punch and an inner periphery of the second opening through the first opening, and a secondary pressurizing step of the upper punch applying secondary pressure downward to the pouch film through the second opening.

[0016] In the first pressurizing step, the lower punch may enter the second opening from the first opening.

[0017] In the second pressurizing step, the lower punch may be removed from the first opening.

[0018] In the second pressurizing step, the upper punch may enter the inside of the first opening from the second opening.

[0019] A pouch-type battery case according to an embodiment of the present invention may include a cup portion having a recessed shape and a terrace located on a periphery of the cup portion. The periphery of the cup portion may include a first periphery connected to the terrace by a die edge, a second periphery connected to the first periphery and having a thickness thinner than the first periphery, and a third periphery connected to the second periphery and connected to a base of the cup portion by a punch edge and having a thickness thicker than the second periphery.

[0020] The thickness of the first periphery may correspond to the thickness of the third periphery and / or the thickness of the die edge.

[0021] The thickness of the second circumferential portion and the thickness of the punch edge may correspond to each other.

[0022] The thickness of the second peripheral portion may be less than the thickness of the die edge. [Effects of the Invention]

[0023] According to a preferred embodiment of the present invention, a deep cup portion can be formed without causing cracks in the pouch film. More specifically, in conventional methods, a cup portion is formed by a single pressurization, which results in excessive stretching of only specific regions of the pouch film, and therefore the depth of the cup portion has been limited to prevent cracks from occurring. In contrast, the present invention has the advantage that the forming process is performed multiple times so that regions of the pouch film that were not previously stretched are also stretched, thereby ultimately allowing for a deeper cup portion to be formed.

[0024] Other effects may be included that can be easily predicted by a person skilled in the art from the configuration according to the preferred embodiment of the present invention. [Brief explanation of the drawings]

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention and, together with the detailed description of the invention described below, serve to further understand the technical concept of the present invention. Therefore, the present invention should not be interpreted as being limited solely to the matters depicted in such drawings. [Figure 1] 1 is a schematic diagram of a molding apparatus according to one embodiment of the present invention. [Figure 2] 3A to 3C are schematic diagrams sequentially illustrating the operation of a molding device according to an embodiment of the present invention. [Figure 3] 3A to 3C are schematic diagrams sequentially illustrating the operation of a molding device according to an embodiment of the present invention. [Figure 4] 3A to 3C are schematic diagrams sequentially illustrating the operation of a molding device according to an embodiment of the present invention. [Figure 5] 3A to 3C are schematic diagrams sequentially illustrating the operation of a molding device according to an embodiment of the present invention. [Figure 6] 4 is a flowchart of a molding method according to another embodiment of the present invention. [Figure 7] 5A to 5C are schematic views illustrating a molding process of a pouch-type battery case according to still another embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] The present invention will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily understand the preferred embodiments of the present invention. However, the present invention can be realized in various different forms and is not limited to the following embodiments.

[0027] In order to clearly explain the present invention, detailed descriptions of parts that are not relevant to the explanation or related known technologies that may obscure the gist of the present invention will be omitted, and when assigning reference symbols to components in each drawing in this specification, the same or similar reference symbols will be assigned to the same or similar components throughout the specification.

[0028] Furthermore, the terms and words used in this specification and claims should not be interpreted in a limited way to their ordinary or dictionary meanings, but should be interpreted in a way that is consistent with the technical idea of ​​the present invention, in accordance with the principle that an inventor can appropriately define the concept of a term in order to best explain his or her invention.

[0029] FIG. 1 is a schematic diagram of a molding apparatus according to one embodiment of the present invention, and FIGS. 2 to 5 are schematic diagrams sequentially showing the operation of a molding apparatus according to one embodiment of the present invention.

[0030] The forming device according to one embodiment of the present invention can form a pouch film 100. The pouch film 100 may have a predetermined thickness. The pouch film 100 may be a formable laminate sheet. More specifically, the pouch film 100 may be a laminate sheet in which a pair of resin layers located on both outermost sides and a metal layer located between the pair of resin layers are laminated.

[0031] A molding apparatus according to one embodiment of the present invention may include a die 10 , a stripper 20 , an upper punch 30 and a lower punch 40 .

[0032] Some of the die 10, the stripper 20, the upper punch 30, and the lower punch 40 may be configured to be able to move up and down relative to the others. As an example, any one of the die 10, the stripper 20, the upper punch 30, and the lower punch 40 may be fixed, and the others may be configured to be able to move up and down independently of the any one of the above. As another example, each of the die 10, the stripper 20, the upper punch 30, and the lower punch 40 may be configured to be able to move up and down independently of the any one of the above.

[0033] The die 10 may be located below the pouch film 100. A first opening 12 may be formed in the die 10. The first opening 12 may be formed by penetrating from the upper surface of the die 10 downward. The first opening 12 may be a forming space in which the pouch film 100 is formed by depression. The first opening 12 may also be a space in which a lower punch 40, which will be described later, is disposed.

[0034] The cross section of the first opening 12 may be substantially rectangular, but is not limited to this.

[0035] The die 10 may have a curved edge 11. More specifically, the upper surface of the die 10 and the inner periphery of the first opening 12 may be connected by the curved edge 11. The edge 11 may have a predetermined radius of curvature. By forming the edge 11 in a curved shape, it is possible to prevent the portion of the pouch film 100 that is in close contact with the edge 11 from breaking when the pouch film 100 is stretched into the first opening 12.

[0036] The stripper 20 may face the die 10 via the pouch film 100. The stripper 20 may fix the pouch film 100 on the upper side of the die 10.

[0037] More specifically, at least one of the die 10 and the stripper 20 may be configured to be movable up and down, and the distance between the die 10 and the stripper 20 may be variable. The pouch film 100 may enter between the die 10 and the stripper 20 when the die 10 and the stripper 20 are separated from each other, and then be fixed between the die 10 and the stripper 20 when the die 10 and the stripper 20 approach each other. That is, the pouch film 100 may be fixed between the top surface of the die 10 and the bottom surface of the stripper 20.

[0038] A second opening 22 may be formed in the stripper 20. The second opening 22 may be formed to penetrate upward from the bottom surface of the stripper 20. The second opening 22 may be a space in which an upper punch 30, which will be described later, is disposed.

[0039] The cross section of the second opening 22 may be, but is not limited to, a substantially rectangular shape. The second opening 22 may be located above the first opening 12. The second opening 22 and the first opening 12 may face each other with the pouch film 100 interposed therebetween.

[0040] The stripper 20 may have a curved edge 21. More specifically, the bottom surface of the stripper 20 and the inner periphery of the second opening 22 may be connected by the curved edge 21. The edge 21 may have a predetermined radius of curvature. By forming the edge 21 in a curved shape, it is possible to prevent the portion of the pouch film 100 that is in close contact with the edge 21 from breaking when the pouch film 100 is stretched into the second opening 22.

[0041] The upper punch 30 may pressurize the pouch film 100 through the second opening 22 .

[0042] The height of the upper punch 30 relative to the die 10 may be variable within the second opening 22. More specifically, at least one of the die 10 and the upper punch 30 may be configured to be movable up and down, and the height difference between the top surface of the die 10 and the bottom surface of the upper punch 30 may be variable.

[0043] The upper punch 30 may have a curved edge 31. More specifically, the upper surface and the outer periphery of the sub-die 30 may be connected by the curved edge 31. The edge 31 may have a predetermined radius of curvature. By forming the edge 31 in a curved shape, it is possible to prevent the portion of the pouch film 100 that is in close contact with the edge 31 from breaking when the pouch film 100 is stretched into the first opening 12.

[0044] The lower punch 40 may press the pouch film 100 between the outer periphery of the upper punch 30 and the inner periphery of the second opening 22 through the first opening 12. The lower punch 40 may face between the outer periphery of the upper punch 30 and the inner periphery of the second opening 22 through the pouch film 100.

[0045] The height of the lower punch 40 relative to the die 10 may be variable within the first opening 12. More specifically, at least one of the die 10 and the lower punch 40 may be configured to be movable up and down, and the height difference between the upper surface of the die 10 and the upper surface of the lower punch 40 may be variable.

[0046] The upper surface of the lower punch 40 may be curved. The upper surface 41 of the lower punch 40 may have a predetermined radius of curvature. The upper surface 41 of the lower punch 40 may be formed in a bulging state. By doing so, it is possible to prevent the portion of the pouch film 100 that is in close contact with the upper surface 41 of the lower punch 40 from breaking when the lower punch 40 presses the pouch film 100. However, this is not limited thereto, and the upper surface 41 of the lower punch 40 may be formed flat and connected to the outer and inner peripheries of the lower punch 40 by edges that are curved.

[0047] 2, during primary forming in which the lower punch 40 presses the pouch film 100, the lower punch 40 may protrude above the upper surface of the die 10. At this time, the upper punch 30 may be located in the second opening 22. More specifically, the bottom surface of the upper punch 30 may be located on the same horizontal plane as the bottom surface of the stripper 20.

[0048] 3 and 4, during secondary forming in which the upper punch 30 presses the pouch film 100, the lower punch 40 may be removed from the first opening 12. Therefore, the upper punch 30 can sufficiently pressurize the pouch film 100 downward without the pouch film 100 interfering with the lower punch 40. More specifically, the upper punch 30 can pressurize the pouch film 100 to a depth that protrudes downward from the first opening 12.

[0049] The operation of the molding apparatus according to one embodiment of the present invention will be described below. For convenience of explanation, the following will be described taking as an example a case where the die 10 is fixed and the stripper 20, upper punch 30, and lower punch 40 each move up and down independently.

[0050] Referring to Figure 1, when the pouch film 100 enters between the die 10 and the stripper 20, the stripper 20 descends toward the die 10, thereby fixing a portion of the outer side of the pouch film 100 between the stripper 20 and the die 10.

[0051] 2, the upper punch 30 may be aligned so that its bottom surface is flush with the bottom surface of the stripper 20. In this state, the lower punch 40 rises from the first opening 12 into the second opening 22, and the pouch film 100 can be pressed between the outer periphery of the upper punch 30 and the inner periphery of the second opening 22. Thus, the portion of the pouch film 100 fixed between the die 10 and the stripper 20 and the portion abutting the upper punch 30 can be kept flat, and the portion pressed by the lower punch 40 can be stretched. This type of pressure molding is called primary molding, and protrusions 110 can be formed in the pouch film 100 by this primary molding.

[0052] 3 and 4, the lower punch 40 can be lowered from the first opening 12. More specifically, the lower punch 40 can be lowered and removed from the first opening 12. The upper punch 30 can be lowered from the second opening 22 into the first opening 12 to apply downward pressure to the pouch film 100. This pressure forming is called secondary forming, and the protruding portion 110 already formed in the pouch film 100 expands through this secondary forming, thereby forming the cup portion 120. The cup portion 120 may be formed by being depressed in the direction opposite to the direction in which the protruding portion 110 is protruded.

[0053] 5, the upper punch 30 can rise and return to its initial position. The stripper 20 also rises, thereby releasing the pouch film 100 that was fixed between the die 10 and the stripper 20.

[0054] Through this series of processes, the formation of the cup portion 120 in the pouch film 100 can be completed. Conventionally, the cup portion was formed by a single pressurization, but in that case, only a specific region of the pouch film was excessively stretched, and the depth of the cup portion was limited to prevent cracks from occurring. In contrast, the present invention has the advantage that the formation is performed multiple times so that regions of the pouch film 100 that were not previously stretched are also stretched, thereby ultimately forming the cup portion 120 deeper.

[0055] FIG. 6 is a flowchart of a molding method according to another embodiment of the present invention.

[0056] Hereinafter, as another embodiment of the present invention, a molding method for molding the pouch film 100 using the above-mentioned molding device will be described.

[0057] A molding method according to another embodiment of the present invention may include a fixing step (S10) (hereinafter referred to as the "fixing step") of fixing the pouch film 100 between the die 10 and the stripper 20, a primary pressure step (S20) (hereinafter referred to as the "primary molding step") of the lower punch 40 applying primary pressure to the pouch film 100 between the outer periphery of the upper punch 30 and the inner periphery of the second opening 22, and a secondary pressure step (S30) (hereinafter referred to as the "secondary molding step") of the upper punch 30 applying secondary pressure downward to the pouch film 100.

[0058] The above-described explanation of the operation of the molding apparatus can be applied to each of steps S10, S20, and S30. More specifically, the fixing step (S10) can be applied to the content explained with reference to Fig. 1, the primary molding step (S20) can be applied to the content explained with reference to Fig. 2, and the secondary molding step (S30) can be applied to the content explained with reference to Figs. 3 to 5. The main features will be briefly described below.

[0059] In the fixing step (S10), the pouch film 100 may be fixed between the top surface of the die 10 and the bottom surface of the stripper 20.

[0060] In the primary forming step (S20), the lower punch 40 may enter the second opening 22 from the first opening 12 while applying pressure to the pouch film 100. More specifically, the lower punch 40 may enter between the inner periphery of the second opening 22 and the outer periphery of the upper punch 30. Thus, the lower punch 40 can form a protrusion 110 in the pouch film 100.

[0061] In the secondary forming step (S30), the upper punch 30 may enter the first opening 12 from the second opening 22 while applying pressure to the pouch film 100. More specifically, the upper punch 30 may apply downward pressure to the center of the pouch film 100 to expand the protruding portion 110 and form the cup portion 120.

[0062] FIG. 7 is a schematic view illustrating a molding process for a pouch-type battery case according to still another embodiment of the present invention.

[0063] Hereinafter, as still another embodiment of the present invention, a pouch-type battery case manufactured by the above-described molding device or molding method will be described.

[0064] A pouch-type battery case (hereinafter, referred to as a “battery case”) according to yet another embodiment of the present invention may include a cup portion 120 having a recessed shape and a terrace 130 located on the periphery of the cup portion 120 .

[0065] The cup portion 120 may form a space for accommodating an electrode assembly (not shown). The terrace 130 may be a portion of the pouch film 100 that is fixed between the die 10 and the stripper 20 and does not have the cup portion 120.

[0066] In the manufacturing process of the battery case, the protrusion 110 may be primarily formed, and the protrusion 110 may be expanded to form the cup portion 120, which is recessed in the opposite direction to the protrusion 110, as a secondary formation.

[0067] The protrusion 110 may include an outer circumferential portion 111 , an inner circumferential portion 112 , and a connecting portion 113 .

[0068] The outer periphery 111 may be connected to the terrace 130 by a stripper edge 114. The stripper edge 114 may be curved. More specifically, the stripper edge 114 may have a predetermined radius of curvature. The stripper edge 114 may be formed by the edge 21 of the stripper 20 (see FIG. 1 ) and may have a radius of curvature corresponding to the edge 21 of the stripper 20.

[0069] The inner peripheral portion 112 may be connected to the central portion 101 by a connecting edge 115. The central portion 101 may be a portion supported by the upper punch 30 during primary molding of the pouch film 100, where the protruding portion 110 is not formed.

[0070] The connecting edge 115 may be a portion that is pressed by the upper punch 30. More specifically, a portion that contacts the edge 31 (see FIG. 1 ) of the upper punch 30 due to relative movement of the lower punch 40 with respect to the upper punch 30 may extend as the connecting edge 115. The connecting edge 115 may be formed in a curved shape. The connecting edge 115 may have a radius of curvature that corresponds to the edge 31 of the upper punch 30.

[0071] The connecting portion 113 may connect the outer circumferential portion 111 and the inner circumferential portion 112. The connecting portion 113 may have a shape corresponding to the upper surface 41 of the lower punch 40. The connecting portion 113 may have a predetermined radius of curvature. The connecting portion 113 may be formed in an upwardly bulging state.

[0072] During the primary molding of the pouch film 100, the terraces 130 and the central portion 101 may not be stretched or may be stretched slightly, so that the remaining thickness may be large.

[0073] The connecting portion 113 may have a smaller remaining thickness due to being directly pressed by the lower punch 40 and stretched relatively more. Similarly, the connecting edge 115 may have a smaller remaining thickness due to being directly pressed by the upper punch 30 and stretched relatively more. The connecting portion 113 and the connecting edge 115 may be stretched to the same or approximately the same extent. Therefore, the remaining thicknesses of the connecting portion 113 and the connecting edge 115 in the protrusion 110 may be the same or approximately the same.

[0074] Furthermore, the outer circumferential portion 111 and the inner circumferential portion 112 may extend relatively less than the connecting portion 113 and the connecting edge 115. The stripper edge 114 may also extend to the same extent as or the same degree as the outer circumferential portion 111 and the inner circumferential portion 112. Therefore, in the protruding portion 110, the remaining thicknesses of the outer circumferential portion 111, the inner circumferential portion 112, and the stripper edge 114 may be the same or the same extent.

[0075] That is, the thickness of each of the outer circumferential portion 111 , the inner circumferential portion 112 and the stripper edge 114 may be thicker than the thickness of each of the connecting portion 113 and the connecting edge 115 , and thinner than the thickness of the terrace 130 and the central portion 101 .

[0076] During secondary molding of the pouch film 100, the stripper edge 114 and outer peripheral portion 111 of the protruding portion 110 may form the die edge 123 of the cup portion 120 and a first peripheral portion 122a that is a part of the peripheral portion 122 of the cup portion 120. The connecting portion 113 of the protruding portion 110 may form the second peripheral portion 122b that is another part of the peripheral portion 122 of the cup portion 120. The inner peripheral portion 112 of the protruding portion 110 may form the third peripheral portion 122c that is yet another part of the peripheral portion 122 of the cup portion 120. The connecting edge 115 and central portion 101 of the protruding portion 110 may form the punch edge 124 and base portion 121 of the cup portion 120.

[0077] Therefore, taking the cross-sectional view of Figure 7 as a reference, in the protrusion 110, the length of the stripper edge 114 is L1, the length of the outer peripheral portion 111 is L2, the length of the connecting portion 113 is L3, the length of the inner peripheral portion 112 is L4, the length of the connecting edge 115 is L5, and the length of the central portion 101 is L6, and in the cup portion 120, the length of the die edge 123 is L7, the length of the peripheral portion 122 is L8, the length of the punch edge is L9, and the length of the base portion is L10, the conditional expression 2*(L1+L2+L3+L4+L5)+L6=2*(L7+L8+L9)+L10 may be satisfied.

[0078] However, this is not limited to this, and if the upper punch 30 further extends the cup portion 120, the condition 2*(L1+L2+L3+L4+L5)+L6<2*(L7+L8+L9)+L10 may be satisfied.

[0079] The length L1 of the stripper edge 114 may refer to the length from a boundary P1 between the terrace 130 and the stripper edge 114 to a boundary P2 between the stripper edge 114 and the outer periphery 111. The length L2 of the outer periphery 111 may refer to the length from the boundary P2 between the stripper edge 114 and the outer periphery 111 to a boundary P3 between the outer periphery 111 and the connecting portion 113. The length L3 of the connecting portion 113 may refer to the length from the boundary P3 between the outer periphery 111 and the connecting portion 113 to a boundary P4 between the connecting portion 113 and the inner periphery 112. The length L4 of the inner periphery 112 may refer to the length from the boundary P4 between the connecting portion 113 and the inner periphery 112 to a boundary P5 between the inner periphery 112 and the connecting edge 115. The length L5 of the connecting edge 115 may refer to the length from the boundary P5 between the inner periphery 112 and the connecting edge 115 to the boundary P6 between the connecting edge 115 and the central portion 101. The length L6 of the central portion 101 may refer to the length between the boundaries P6 between both connecting edges 115 and the central portion 101.

[0080] The length L7 of the die edge 123 may refer to the length from the boundary P1 between the terrace 130 and the die edge 123 to the boundary P7 between the die edge 123 and the peripheral portion 122. The length L8 of the peripheral portion 122 may refer to the length from the boundary P7 between the die edge 123 and the peripheral portion 122 to the boundary P8 between the peripheral portion 122 and the punch edge 124. The length L9 of the punch edge 124 may refer to the length from the boundary P8 between the peripheral portion 122 and the punch edge 124 to the boundary P9 between the punch edge 124 and the base portion 121. The length L10 of the base portion 121 may refer to the length between the boundaries P9 between both punch edges 124 and the base portion 121.

[0081] The cup portion 120 is formed by widening the protrusion 110, so that the thickness of each portion of the cup portion 120 differs from that of a cup portion formed by a conventional method. The cup portion 120 will be described below.

[0082] The cup portion 120 may include a base portion 121 and a perimeter portion 122 .

[0083] The periphery 122 of the cup portion 120 may be connected to the terrace 130 by a die edge 123. The die edge 123 may be curved. More specifically, the die edge 123 may have a predetermined radius of curvature. The die edge 123 may be formed by the edge 11 of the die 10 (see FIG. 1 ) and may have a radius of curvature corresponding to the edge 11 of the die 10.

[0084] The base portion 121 of the cup portion 120 may be connected to the peripheral portion 122 by a punch edge 124. The punch edge 124 may be formed in a curved shape. More specifically, the punch edge 124 may have a predetermined radius of curvature. The punch edge 124 may be formed by the edge 31 of the upper punch 30 (see FIG. 1 ), and may have a radius of curvature corresponding to the edge 31 of the upper punch 30. The punch edge 124 may be a portion corresponding to the connecting edge 115 formed when the preceding protrusion 110 was formed.

[0085] The peripheral portion 122 of the cup portion 120 may include a first peripheral portion 122a connected to the terrace 130 by a die edge 123, a second peripheral portion 122b connected to the first peripheral portion 122a and having a thickness thinner than the first peripheral portion 122a, and a third peripheral portion 122c connected to the second peripheral portion 122b, connected to the base portion 121 by a punch edge 124, and having a thickness thicker than the second peripheral portion 122b.

[0086] The first circumferential portion 122a may correspond to the outer circumferential portion 111 of the protruding portion 110, the second circumferential portion 122b may correspond to the connecting portion 113 of the protruding portion 110, and the third circumferential portion 122c may correspond to the inner circumferential portion 112 of the protruding portion 110. As described above, the remaining thickness of the connecting portion 113 may be thinner than the remaining thicknesses of the outer circumferential portion 111 and the inner circumferential portion 112, and therefore the thickness t2 of the second circumferential portion 122b may be relatively thinner than the thickness t1 of the first circumferential portion 122a and the thickness t3 of the third circumferential portion 122c.

[0087] As described above, the remaining thicknesses of the outer peripheral portion 111, the inner peripheral portion 112, and the stripper edge 114 of the protrusion 110 may be the same or approximately the same. Therefore, the thickness t1 of the first peripheral portion 122a of the cup portion 120 and the thickness t3 of the third peripheral portion 122c may be the same or approximately the same, i.e., correspond to each other. Furthermore, the thickness t1 of the first peripheral portion 122a of the cup portion 120 and the thickness t5 of the die edge 123 may correspond to each other. Furthermore, the thickness t2 of the second peripheral portion 122b of the cup portion 120 may be thinner than the thickness t5 of the die edge 123.

[0088] As described above, the remaining thicknesses of the connecting portion 113 and the connecting edge 115 of the protrusion 110 may be the same or approximately the same. Therefore, the thickness t2 of the second circumferential portion 122b of the cup portion 120 and the thickness t6 of the punch edge 124 may correspond to each other. Furthermore, the thickness t6 of the punch edge 124 may be thinner than the thickness t5 of the die edge 123, the thickness t1 of the first circumferential portion 122a, and the thickness t3 of the third circumferential portion 122c.

[0089] Meanwhile, the base portion 121 of the cup portion 120 may be a portion corresponding to the central portion 101 at the time of the primary molding. As described above, the thickness of the central portion 101 may be relatively thicker than each portion of the protruding portion 110. Therefore, the thickness t4 of the base portion 121 of the cup portion 120 may be thicker than the thicknesses t1, t2, t3 of the first to third peripheral portions 122a, 122b, 122c, the thickness t5 of the die edge 123, and the thickness t6 of the punch edge 124.

[0090] The above description merely exemplifies the technical concept of the present invention, and various modifications and variations may be made by a person having ordinary knowledge in the technical field to which the present invention pertains without departing from the essential characteristics of the present invention.

[0091] Therefore, the embodiments disclosed in the present invention are for illustrative purposes only and are not intended to limit the technical idea of ​​the present invention, and the scope of the technical idea of ​​the present invention is not limited by such embodiments.

[0092] The scope of protection of the present invention should be interpreted by the appended claims, and all technical ideas within the scope equivalent thereto should be interpreted as being included in the scope of the present invention. [Explanation of symbols]

[0093] 10 Die 12 First opening 20 Stripper 22 Second opening 30 Upper Punch 40 Lower Punch 100 pouch film 101 Central part 110 Protrusion 111 Outer periphery 112 Inner circumference 113 Connecting part 114 Stripper Edge 115 Connected Edges 120 Cup section 121 Base 122 Periphery 122a 1st lap 122b 2nd circumference 122c 3rd circumference 123 Die Edge 124 Punch Edge 130 Terrace

Claims

1. A molding device for forming a cup portion in a pouch film, a die having a first opening formed therein; a stripper that fixes the pouch film above the die, the stripper having a second opening formed at a position corresponding to the first opening; an upper punch that pressurizes the pouch film through the second opening; a lower punch that pressurizes the pouch film between the outer periphery of the upper punch and the inner periphery of the second opening through the first opening,

2. the lower punch applies a first pressure to the pouch film while the upper punch is positioned at the second opening; The forming device according to claim 1 , wherein the upper punch applies a second pressure to the pouch film while the lower punch is separated from the first opening.

3. The forming device according to claim 2 , wherein the upper punch presses the pouch film to a depth at which the upper punch protrudes downward from the first opening.

4. 4. The molding apparatus according to claim 1, wherein the upper surface of the lower punch is formed in a bulging state.

5. A molding method for forming a cup portion in a pouch film, a fixing step of fixing the pouch film between a die having a first opening and a stripper having a second opening; a primary pressurizing step in which a lower punch applies primary pressure to the pouch film between an outer periphery of the upper punch and an inner periphery of the second opening through the first opening; a secondary pressurizing step in which the upper punch applies a second downward pressure to the pouch film through the second opening.

6. The molding method according to claim 5 , wherein in the first pressurizing step, the lower punch advances from the first opening into the second opening.

7. The molding method according to claim 5 , wherein in the second pressurizing step, the lower punch is removed from the first opening.

8. The molding method according to any one of claims 5 to 7, wherein in the secondary pressurizing step, the upper punch advances from the second opening into the first opening.

9. a cup portion having a recessed shape; a terrace located on the periphery of the cup portion, The periphery of the cup portion is a first circumferential portion connected to the terrace by a die edge; a second circumferential portion connected to the first circumferential portion and having a thickness thinner than that of the first circumferential portion; a third periphery connected to the second periphery and connected to a base of the cup portion by a punch edge, the third periphery having a thickness greater than that of the second periphery;

10. The pouch-type battery case according to claim 9 , wherein the thickness of the first periphery corresponds to the thickness of the third periphery and / or the thickness of the die edge.

11. The pouch-type battery case according to claim 9 or 10, wherein the thickness of the second circumferential portion and the thickness of the punch edge correspond to each other.

12. The pouch-type battery case according to claim 9 , wherein the thickness of the second periphery is thinner than the thickness of the die edge.

Images