Pouch molding apparatus

Abstract

The objective of a pouch molding apparatus related to one embodiment of the present invention is to mold a cup part in a preliminary molding region of a pouch sheet, and comprises: a first die part which has a mold opening, and on which a pouch sheet is loaded such that the preliminary molding region covers the mold opening; a first pressing part for fixing the pouch sheet to the first die part; and a stretching part including a first stretching member for pressing a center region of the preliminary molding region of the pouch sheet, and a second stretching member for pressing a first edge region that surrounds the center region, wherein the first and second stretching members can press the center region and the first edge region, respectively, in different directions of facing the mold opening.

Description

Pouch forming device

[0001] The present invention relates to a pouch forming device, and more particularly, to a pouch forming device capable of forming a cup portion by first stretching a pre-forming area of ​​a pouch sheet and then secondly stretching the first-stretched pre-forming area.

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0167445, filed November 28, 2023, the entire contents of which are incorporated herein by reference.

[0003] Fig. 1 is a schematic diagram of a conventional pouch forming device, Fig. 2 (a) is a perspective view of a pouch provided with a cup portion formed by a conventional pouch forming device, and Fig. 2 (b) is a cross-sectional view taken along line XX of Fig. 2 (a).

[0004] The above pouch forming device (10) includes a die portion (20) provided with a mold groove (22), a punching block (30) provided to be inserted into the mold groove (22), and a stripper (40) for fixing a pouch sheet (1) to the die upper surface (21) of the die portion (20).

[0005] When forming a pouch having the above cup portion (2), the pouch sheet (1) is placed on the upper surface (21) of the die so as to cover the mold groove (22). The pouch sheet (1) is fixed to the die portion (20) by a stripper (40).

[0006] Next, the punching block (30) moves in a direction (F2) approaching the mold groove (22) to extend the central portion of the pouch sheet (1) into the mold groove (22), thereby forming a cup portion (2) on the pouch sheet (1). The punching block (30) is for forming the cup portion (2) and may have a block shape of approximately a rectangular parallelepiped.

[0007] In the manufacturing process of a battery cell, the cup portion (2) of the pouch is a portion where an electrode assembly (not shown) is stored. The electrode assembly (not shown) is a positive electrode and a negative electrode sequentially laminated with a separator as a medium.

[0008] Depending on the product specifications, the thicker the electrode assembly (not shown), the deeper the molding depth (D) of the cup portion (2). In addition, in a pouch provided with one cup portion (2), the molding depth (D) of the cup portion (2) must be provided at a depth that allows the electrode assembly (not shown) to be accommodated.

[0009] When the above pouch sheet (1) is stretched by the punching block (30), stress is concentrated on the block corner portions (34, 35) of the punching block (30). As illustrated in Fig. 2, the cup corner portions (4, 5) of the cup portion (2) that contact the block corner portions (34, 35) of the punching block (30) may be stretched more than the cup bottom surface (3). Accordingly, the cup corner portions (4, 5) may be stretched to a thickness thinner than the thickness of the cup bottom surface (3).

[0010] As the forming depth (D) of the cup portion (2) increases, the thickness of the cup corner portion (4, 5) may also become thinner. In addition, the cup corner portion (4, 5) may be stretched to a thickness thinner than the thickness of the cup bottom surface (3), which may cause cracks to form.

[0011] The forming depth (D) of the above cup portion (2) can be a factor that limits the product specifications of the battery cell, and therefore, a pouch forming device (10) capable of forming the cup portion (2) with a forming depth (D) according to the product specifications is required.

[0012] The purpose of the present invention is to provide a pouch forming device capable of forming a cup portion by first stretching a pre-forming area of ​​a pouch sheet and then secondly stretching the first-stretched pre-forming area.

[0013] A pouch forming device according to one embodiment of the present invention is for forming a cup portion in a pre-forming area of ​​a pouch sheet, the device comprising: a first die portion having a mold opening and a pouch sheet provided to be seated such that the pre-forming area covers the mold opening; a first pressing portion for fixing the pouch sheet to the first die portion; and an elongating portion including a first elongating member provided to press a central area of ​​the pre-forming area of ​​the pouch sheet and a second elongating member provided to press a first edge area surrounding the central area, wherein the first and second elongating members may be provided to press the central area and the first edge area, respectively, in different directions toward the mold opening.

[0014] In one embodiment of the present invention, the second elongating member may be arranged to simultaneously pressurize a plurality of first points along the circumferential direction of the first edge region.

[0015] In one embodiment of the present invention, the second elongation member may be provided such that a virtual first line connecting the plurality of first points forms a closed curve.

[0016] In one embodiment of the present invention, the second elongation member may be provided so that a virtual first line connecting the plurality of first points has a circular shape with a radius larger than a central region.

[0017] In one embodiment of the present invention, the second elongation member may be provided such that the virtual first line connecting the plurality of first points has a polygonal shape.

[0018] In one embodiment of the present invention, the second elongation member may be provided so that the plurality of first points are spaced apart from the central region at a predetermined interval.

[0019] In one embodiment of the present invention, the stretching portion further includes a third stretching member configured to press a second edge region surrounding the first edge region, and the second stretching member and the third stretching member may be configured to press the first edge region and the second edge region, respectively, along different directions toward the mold opening.

[0020] In one embodiment of the present invention, the third elongating member may be arranged to simultaneously pressurize a plurality of second points along the circumferential direction of the second edge region.

[0021] In one embodiment of the present invention, the third extension member may be provided so that a virtual second line connecting the plurality of second points forms a closed curve.

[0022] In one embodiment of the present invention, the third extension member may be provided so that a virtual second line connecting the plurality of second points has a circular shape with a radius larger than that of the first edge region.

[0023] In one embodiment of the present invention, the third extension member may be provided such that the virtual second line connecting the plurality of second points has a polygonal shape.

[0024] In one embodiment of the present invention, the second elongation member and the third elongation member may be provided so that the virtual first line and the virtual second line each have a circular shape.

[0025] In one embodiment of the present invention, the second elongation member and the third elongation member may be provided so that the virtual first line and the virtual second line each have a polygonal shape.

[0026] In one embodiment of the present invention, the pouch forming device may further include a control unit configured to control movement of the first to third elongating members.

[0027] In one embodiment of the present invention, the control unit may be arranged to cause the first and third elongation members to simultaneously pressurize the pre-forming region.

[0028] In one embodiment of the present invention, the control unit may be arranged to simultaneously pressurize the first to third elongation members in the pre-forming region.

[0029] In one embodiment of the present invention, the first to third elongation members may be formed as curved portions in a portion that comes into contact with the pre-forming area.

[0030] In one embodiment of the present invention, the first to third elongating members may have balls rotatably arranged in a portion that contacts the pre-forming area.

[0031] A pouch forming device according to one embodiment of the present invention includes a second die section having a mold groove in which the preformed area formed through the stretching section is seated, a second pressurizing section for fixing the pouch sheet seated in the second die section, and a punching block provided to be insertable into the mold groove, and may further include a punching section provided to stretch the preformed area into the mold groove.

[0032] As described above, the pouch forming device according to one embodiment of the present invention has the following effects.

[0033] The conventional pouch forming device has a problem in that stress is concentrated on the cup corner of the cup part, which is the part pressed by the block corner of the punching block, by stretching the pouch sheet into the mold groove to form the cup part, and the thickness of the cup corner part is stretched thinner than the thickness of the cup bottom surface of the cup part.

[0034] A pouch forming device related to one embodiment of the present invention can form a cup portion by first stretching a pre-forming area of ​​the pouch sheet in which a cup portion is to be formed so as to be curved up and down the pouch sheet, and then secondarily stretching the first-stretched pouch using a punching block.

[0035] The above pouch forming device can prevent stress from being concentrated in the block corners by pressing the first-extended portion of the block corners of the punching block.

[0036] Due to this, the cup part can be formed with a uniform thickness of the cup bottom surface and the cup corner part, thereby eliminating the elongation imbalance of the conventional cup corner part.

[0037] In addition, when forming a cup part, it is possible to resolve the elongation imbalance of the cup corner part, thereby preventing a decrease in the thickness of the cup corner part and the occurrence of cracks in the cup corner part.

[0038] In addition, the cup portion can be formed by first stretching the pre-forming area of ​​the pouch sheet to a forming depth according to the final product specifications, and then stretching the first-stretched pouch into a mold groove having a forming depth.

[0039] Figure 1 is a schematic diagram of a conventional pouch forming device.

[0040] Fig. 2 (a) is a perspective view of a pouch provided with a cup portion formed by a pouch forming device according to a conventional technique, and Fig. 2 (b) is a cross-sectional view taken along line XX of Fig. 2 (a).

[0041] Figure 3 schematically illustrates a configuration diagram of a pouch forming device according to one embodiment of the present invention.

[0042] FIG. 4 is an exemplary diagram dividing a pre-forming area of ​​a pouch sheet into a plurality of areas in one embodiment of the present invention.

[0043] FIG. 5 is a diagram showing the arrangement of a plurality of elongation members as viewed from the top of the first die section according to the present embodiment. FIG. 5(a) is a diagram showing the arrangement of a plurality of elongation members having a circular ring cross-section, FIG. 5(b) is a diagram showing the arrangement of a plurality of elongation members having a square ring cross-section, and FIG. 5(c) is a diagram showing the arrangement of a plurality of elongation members having a polygonal ring cross-section.

[0044] Figures 6 and 7 are operation status diagrams of the extension unit in one embodiment of the present invention.

[0045] Fig. 8 (a) is a perspective view of a first-stretched pouch according to one embodiment of the present invention, and Fig. 8 (b) is a YY cross-sectional view of Fig. 8 (a).

[0046] FIG. 9 and FIG. 10 are drawings for explaining a process of forming a first-stretched pouch into a pouch provided with a cup portion. FIG. 9 is a diagram showing the arrangement of a second die portion, a second pressurizing portion, and a punching portion, and FIG. 10 is a diagram showing the operation of a punching portion in which a punching block of the punching portion is inserted into a mold groove of the second die portion.

[0047] Fig. 11 (a) is a perspective view of a pouch provided with a cup portion according to one embodiment of the present invention, and Fig. 11 (b) is a cross-sectional view of ZZ of Fig. 11 (a).

[0048] Hereinafter, a pouch forming device according to one embodiment of the present invention will be described with reference to the attached drawings.

[0049] In addition, regardless of the drawing symbol, identical or corresponding components are given identical or similar reference numbers and redundant descriptions thereof are omitted, and for the convenience of explanation, the size and shape of each component depicted may be exaggerated or reduced.

[0050] FIG. 3 is a configuration diagram of a pouch forming device according to one embodiment of the present invention, FIG. 4 is an exemplary diagram dividing a pre-forming area of ​​a pouch sheet into a plurality of areas, FIG. 5 is a diagram showing the arrangement of a plurality of stretching members as viewed from the upper portion of a first die section according to the present embodiment, and FIGS. 6 and 7 are operation diagrams of a stretching section according to one embodiment of the present invention.

[0051] A pouch forming device (300) related to one embodiment of the present invention is for forming a cup portion (241) in a pre-forming area (A) of a pouch sheet (200). The pre-forming area (A) is a portion of the pouch sheet (200) that is scheduled to be formed into the cup portion (241).

[0052] As illustrated in FIG. 3, the pouch forming device (300) may include a first die portion (310) provided with a mold opening (312) and provided with a pouch sheet (200) so that the pre-forming area (A) covers the mold opening (312).

[0053] The first die portion (310) has a first die upper surface (311) and a mold opening (312). The first die upper surface (311) is a portion where the pouch sheet (200) is mounted. The mold opening (312) is an opening that penetrates the first die upper surface (311) along a height direction (H). The height direction (H) is a direction perpendicular to the first die upper surface (311).

[0054] As illustrated in FIG. 3, the pouch sheet (200) is mounted on the upper surface (311) of the first die so as to cover the mold opening (312). The lower surface (202) of the pouch sheet (200) is exposed to the upper portion of the first die portion (310) through the mold opening (312).

[0055] Additionally, the pouch forming device (300) may include a first pressurizing portion (320) for fixing the pouch sheet (200) to the first die portion (310). The first pressurizing portion (320) may be a stripper.

[0056] In addition, the pouch forming device (300) may include an elongating section (330) including a first elongating member (331) provided to pressurize a central region (A1) of the pre-forming region (A) of the pouch sheet (200), and a second elongating member (333) provided to pressurize a first edge region (A2) surrounding the central region (A1).

[0057] As illustrated in FIG. 6, the first and second elongation members (331, 333) may be arranged to pressurize the central region (A1) and the first edge region (A2), respectively, along different directions (F1, F2) toward the mold opening (312).

[0058] The first elongation member (331) is positioned so as to be able to enter the mold opening (312) from the lower portion of the first die portion (310). The first elongation member (331) is positioned so as to be able to enter the central portion of the mold opening (312). The first elongation member (331) is provided so as to be able to move up and down along the height direction (H).

[0059] The first elongating member (331) may be formed as a curved portion in a portion that comes into contact with the pre-forming area (A). The first elongating member (331) may have a first ball (332a) rotatably arranged in a portion that comes into contact with the pre-forming area (A).

[0060] A first bearing member (332) having the first ball (332a) may be mounted on the upper end of the first elongating member (331). The first elongating member (331) may be arranged such that the first ball (332a) can be in point contact with the center of the central area (A1) on the lower surface of the pouch sheet (200).

[0061] When the first extension member (331) presses the lower surface of the pouch sheet (200) in the first direction (F1), the first ball (332a) rotates counterclockwise or clockwise while in contact with the lower surface of the pouch sheet (200), thereby dispersing the stress concentrated at the point where the first ball (332a) makes point contact in a direction different from the first direction (F1).

[0062] The first elongation member (331) is mounted on a lower support (337a). A first driving unit (337) is mounted on the lower support (337a). The first driving unit (337) can move the lower support (337a) up or down along the height direction (H), thereby controlling the movement direction and movement distance of the first elongation member (331).

[0063] The first driving unit (337) can be operated to move the lower support (337a) in a first direction (F1) from the lower portion of the mold opening (312) toward the upper portion, so that the first elongating member (331) enters the mold opening (312).

[0064] When the first driving unit (337) is operated, the first extension member (331) enters the mold opening (312) in the first direction (F1) along the height direction (H), and can extend the central area (A1) in contact with the lower surface of the pouch sheet (200) to the upper portion of the mold opening (312).

[0065] Among the above pre-forming areas (A), the central area (A1) can be extended to the upper portion of the mold opening (312) by the force applied by the first extension member (331) in the first direction (F1). Hereinafter, for convenience of explanation, the portion where the central area (A1) is curved to the upper portion of the pouch sheet (200) is referred to as a "first annular portion (231, see FIG. 8)."

[0066] The second elongation member (333) is positioned so as to be able to enter the mold opening (312) from the upper portion of the first die portion (310). The second elongation member (333) is positioned so as to be able to enter the first edge area (A2) of the mold opening (312). The second elongation member (333) is provided so as to be able to move up and down along the height direction (H).

[0067] Referring to FIGS. 4 and 5, the second elongating member (333) may be configured to simultaneously pressurize a plurality of first points along the circumferential direction of the first edge region (A2). The first points may be spaced apart from the center of the preforming region (A) by a first radius (r1).

[0068] The above second extension member (333) may be arranged so that the virtual first line (L1) connecting the plurality of first points forms a closed curve.

[0069] The above second extension member (333) may be provided so that the virtual first line (L1) connecting the plurality of first points has a circular shape with a radius larger than the central area (A1).

[0070] The above second extension member (333) can be provided so that the virtual first line (L1) connecting the plurality of first points has a polygonal shape.

[0071] The second extension member (333) may be formed as a curved portion in contact with the pre-forming area (A).

[0072] A second bearing member (334) having a plurality of second balls (334a) may be mounted on the lower end of the second extension member (333). The second balls (334a) are provided rotatably at a portion that comes into contact with the pre-forming area (A). The second balls (334a) can come into contact with the upper surface (201) of the pouch sheet (200) along the imaginary first line (L1).

[0073] The second extension member (333) may be arranged so that the plurality of second balls (334a) can be in point contact with the first edge area (A2) on the upper surface of the pouch sheet (200) along the virtual first line.

[0074] When the second extension member (333) presses the upper surface of the pouch sheet (200) in the second direction (F2), each of the second balls (334a) rotates counterclockwise or clockwise while in contact with the upper surface of the pouch sheet (200), so that the stress concentrated at the point where each of the second balls (334a) makes point contact can be dispersed in a direction different from the second direction (F2).

[0075] The second elongation member (333) may be provided so that the plurality of first points are spaced apart from the central region (A1) at a predetermined interval. The second elongation member (333) is provided to surround the first elongation member (331) when entering the mold opening (312).

[0076] The second elongation member (333) is mounted on an upper support (338). A second driving unit (339) is mounted on the upper support (338). The second driving unit (339) can move the upper support (338) up or down along the height direction (H), thereby controlling the movement direction and movement distance of the second elongation member (333).

[0077] The second elongation member (333) is mounted on the upper support (338) to surround the first elongation member (331) when entering the mold opening (312).

[0078] The second driving unit (339) can be operated to move the upper support (338) in a second direction (F2) from the upper side to the lower side of the mold opening (312), so that the second elongating member (333) enters the mold opening (312).

[0079] When the second driving unit (339) is operated, the second extension member (333) enters the mold opening (312) in the second direction (F2) along the height direction (H) and can extend the first edge area (A2) in contact with the upper surface of the pouch sheet (200) to the lower portion of the mold opening (312).

[0080] Among the above pre-forming areas (A), the first edge area (A2) can be extended to the lower portion of the mold opening (312) by the force applied by the second extension member (333) in the second direction (F2). Hereinafter, for convenience of explanation, the portion where the first edge area (A2) is curved toward the lower portion of the pouch sheet (200) is referred to as a “second annular portion (233, see FIG. 8).”

[0081] Additionally, the extension member (330) may include a third extension member (335) configured to pressurize a second edge area (A3) surrounding the first edge area (A2).

[0082] Referring to Fig. 3, the third elongation member (335) is positioned so as to be able to enter the mold opening (312) from the lower portion of the first die portion (310). The third elongation member (335) is positioned so as to be able to enter the second edge area (A3) of the mold opening (312). The third elongation member (335) is provided so as to be able to move up and down along the height direction (H).

[0083] The second elongation member (333) and the third elongation member (335) may be arranged to press the first edge area (A2) and the second edge area (A3), respectively, along different directions (F1, F2) toward the mold opening (312).

[0084] Referring to FIGS. 4 and 5, the third elongation member (335) may be configured to simultaneously pressurize a plurality of second points along the circumferential direction of the second edge region (A3). The second points may be spaced apart from the center of the preform region (A) by a second radius (r2).

[0085] The third extension member (335) may be formed as a curved portion in contact with the pre-forming area (A).

[0086] The third extension member (335) may be arranged so that a virtual second line (L2) connecting the plurality of second points forms a closed curve.

[0087] The third extension member (335) may be provided so that the virtual second line (L2) connecting the plurality of second points has a circular shape with a radius larger than the first edge area (A2).

[0088] The third extension member (335) may be provided so that the virtual second line (L2) connecting the plurality of second points has a polygonal shape.

[0089] The second extension member (333) and the third extension member (335) may be provided so that the virtual first line (L1) and the virtual second line (L2) each have a circular shape.

[0090] The second extension member (333) and the third extension member (335) may be provided so that the virtual first line (L1) and the virtual second line (L2) each have a polygonal shape.

[0091] A third bearing member (336) having a plurality of third balls (336a) may be mounted on the upper end of the third extension member (335). The third balls (336a) may be provided rotatably at a portion that comes into contact with the pre-forming area (A).

[0092] The third extension member (335) may be arranged so that the plurality of third balls (336a) can be in point contact with the second edge area (A3) on the lower surface of the pouch sheet (200) along the virtual second line (L2).

[0093] When the third extension member (335) presses the lower surface of the pouch sheet (200) in the first direction (F1), each of the third balls (336a) rotates counterclockwise or clockwise while in contact with the lower surface of the pouch sheet (200), so that the stress concentrated at the point where each of the third balls (336a) makes point contact can be dispersed in a direction different from the first direction (F1).

[0094] The third extension member (335) is mounted on a lower support (337a). A first driving unit (337) is mounted on the lower support (337a). The first driving unit (337) can move the lower support (337a) up or down along the height direction (H), thereby controlling the movement direction and movement distance of the third extension member (335).

[0095] The lower support (337a) moves the first and third elongation members (331, 335) together in the same direction. The third elongation member (335) is mounted on the lower support (337a) so as to surround the first elongation member (331).

[0096] The third elongation member (335) is spaced apart from the first elongation member (331) by a predetermined interval along the width direction (W) of the mold opening (312). The third elongation member (335) can be mounted on the lower support (337a) so as to be adjacent to the inner surface (313, 314) of the mold opening (312) when entering the mold opening (312).

[0097] The first driving unit (337) can be operated to move the lower support (337a) in a first direction (F1) from the lower portion of the mold opening (312) toward the upper portion, so that the third elongating member (335) enters the mold opening (312).

[0098] When the first driving unit (337) is operated, the third extension member (335) enters the mold opening (312) in the first direction (F1) along the height direction (H), and can extend the second edge area (A3) in contact with the lower surface of the pouch sheet (200) to the upper portion of the mold opening (312).

[0099] Among the above pre-forming areas (A), the second edge area (A3) can be extended to the upper portion of the mold opening (312) by the force applied by the first extension member (331) in the first direction (F1). Hereinafter, for convenience of explanation, the portion where the second edge area (A3) is curved to the upper portion of the pouch sheet (200) is referred to as a "third annular portion (235, see FIG. 8)."

[0100] Additionally, the pouch forming device (300) may include a control unit (340) configured to control the movement of the first to third elongation members (331, 333, 335). The control unit (340) controls the operation of the first and second driving units (337, 339).

[0101] The control unit (340) may be arranged so that the first and third elongation members (331, 335) pressurize the pre-forming area (A) simultaneously. The control unit (340) may be arranged so that the first to third elongation members (331, 333, 335) pressurize the pre-forming area (A) simultaneously.

[0102] The above control unit (340) can operate the first driving unit (337) so that the lower support (337a) moves in the first direction (F1) by the forming depth (D) during the stretching operation of the pouch sheet (200), and can operate the second driving unit (339) so that the upper support (338) moves in the second direction (F2) by the forming depth (D).

[0103] As described above, when the first driving unit (337) operates, the lower support (337a) moves in the first direction (F1). The first and third elongating members (331, 335) can elongate the central region (A1) and the second edge region (A3) of the pre-forming region (A) to the upper portion of the mold opening (312) while moving in the first direction (F1) together with the lower support (337a).

[0104] When the second driving unit (339) is operated, the upper support member (338) moves in the second direction (F2). The second elongating member (333) can move in the second direction (F2) together with the upper support member (338) to elongate the first edge region (A2) of the pre-forming region (A) to the lower portion of the mold opening (312). The first edge region (A2) is the region between the central region (A1) and the second edge region (A3).

[0105] The second elongation member (333) presses the upper and lower surfaces of the pouch sheet (200) in different directions (F1, F2) together with the first and third elongation members (331, 335).

[0106] Fig. 8 (a) is a perspective view of a first-stretched pouch according to one embodiment of the present invention, and Fig. 8 (b) is a YY cross-sectional view of Fig. 8 (a).

[0107] By the above process, referring to FIG. 8, the first elongated preformed region (A10) is formed into a first annular portion (231) and a third annular portion (235) by elongating the central region (A1) and the second edge region (A3) to the upper portion of the pouch sheet (200), and the first edge region (A2) is elongated to the lower portion of the pouch sheet (200) to have a second annular portion (233).

[0108] The second annular portion (233) extends downwardly from the first annular portion (231) and the third annular portion (235) along the height direction (H), and is provided to connect the first annular portion (231) and the third annular portion (235) in a curved manner.

[0109] The first to third annular portions (231, 233, 235) may have an annular shape with a circular cross-section or a polygonal cross-section depending on the shape of the first to third elongated members (331, 333, 335).

[0110] FIG. 9 and FIG. 10 are drawings for explaining a process of forming a first-stretched pouch into a pouch provided with a cup portion. FIG. 9 is a diagram showing the arrangement of a second die portion, a second pressurizing portion, and a punching portion, and FIG. 10 is a diagram showing the operation of a punching portion in which a punching block of the punching portion is inserted into a mold groove of the second die portion.

[0111] As shown in FIGS. 9 and 10, the pouch forming device (300) may include a second die section (360), a second pressurizing section (370), and a punching section (380) to form a pouch (230) in which a pre-forming area (A) has been first stretched into a pouch (240, see FIG. 11) provided with a cup section (241).

[0112] For example, the pouch (230) that has been first stretched in the above-mentioned pre-forming area (A) can be transferred to the second die section (360) via a transfer section such as a gripper and / or conveyor.

[0113] The above second die portion (360) has a mold groove (361) having a molding depth (D).

[0114] The above mold groove (361) is provided so that the pre-forming area (A) can be settled in the main forming area (A10) that has been first stretched. The main forming area (A10) is provided with a first annular portion (231), a second annular portion (233), and a third annular portion (235).

[0115] As illustrated in Fig. 9, the first elongated pouch (230) can be placed in the mold groove (361) such that the second annular portion (233) is placed on the groove bottom surface (363) and the first annular portion (231) and the third annular portion (235) are exposed to the upper portion of the mold groove (361). The first elongated pouch (230) is in a state in which the first annular portion (231), the second annular portion (233), and the third annular portion (235) are elongated to a uniform thickness.

[0116] The second pressurizing portion (370) is for fixing the first stretched pouch (230) to the second die portion (360). The second pressurizing portion (370) may be a stripper.

[0117] The above punching section (380) includes a punching block (381) that is provided so as to be insertable into a mold groove (361). The punching block (381) is provided so as to extend the first annular section (231), the second annular section (233), and the third annular section (235) into the mold groove (361).

[0118] As illustrated in Fig. 10, the punching block (381) moves in the second direction (F2) toward the mold groove (361) and presses the first annular portion (231) and the third annular portion (235) exposed to the upper portion of the mold groove (361) while being inserted into the mold groove (361). Then, the punching block (381) presses the second annular portion (233) against the groove bottom surface (363).

[0119] Fig. 11 (a) is a perspective view of a pouch provided with a cup portion according to one embodiment of the present invention, and Fig. 11 (b) is a cross-sectional view of ZZ of Fig. 11 (a).

[0120] The first stretched pouch (230) can be formed into a pouch (240, see Fig. 11) provided with a cup portion (241). As illustrated in Fig. 11, the cup portion (241, see Fig. 11) is provided with a cup bottom surface (242) and cup corner portions (243, 244).

[0121] The cup bottom surface (242) is a portion where the first and second annular portions (231, 233) are extended to contact the groove bottom surface (363). The cup corner portions (243, 244) are portions where the third annular portion (235) is extended to contact the groove corner portions (367, 368) of the mold groove (361). The cup corner portions (243, 244) are portions that connect the inner surface of the cup portion (241, see Fig. 11) that extends in the height direction (H) from the cup bottom surface (242).

[0122] Conventionally, a punching block (30, see Fig. 1) extends a pre-forming area (A) in a flat state into a mold groove (161). Accordingly, stress is concentrated on the cup corner portions (4, 5) that are in contact with the block corner portions (34, 35) of the punching block (30, see Fig. 1), so that the cup corner portions (4, 5, see Fig. 2) are extended more than the cup bottom surface (3, see Fig. 2), and the thickness of the cup corner portions (4, 5, see Fig. 2) is formed to be thinner than the thickness of the cup bottom surface (3, see Fig. 2).

[0123] As illustrated in Fig. 2, the conventional cup portion (2, see Fig. 2) had problems such as cracks occurring in the cup corner portion (4, 5) or breakage of the cup corner portion (4, 5) as the cup corner portion (4, 5) was formed to a thickness thinner than the cup bottom surface (3). Such damage to the cup portion (2) may cause secondary problems such as electrolyte leakage or battery cell explosion due to electrolyte leakage.

[0124] In contrast, the present invention is configured to first elongate the preform region (A) in a curved manner and then form the first-elongated preform region (A) into a cup portion (241, see FIG. 11). Accordingly, when the punching block (381) presses the first-elongated preform region (A) into the mold groove (361), the stress concentration at the cup corner portions (243, 244) where the block corner portions (382) of the punching block (381) are in contact is relieved, and thus the cup corner portions (243, 244) and the cup bottom surface (242) can be formed with a uniform thickness.

[0125] Accordingly, the present invention can prevent damage to the cup portion (241, see FIG. 11) during the pouch manufacturing process, and prevent secondary problems such as leakage of electrolyte caused by damage to the cup portion (241, see FIG. 11) and / or explosion of the battery cell due to leakage of electrolyte.

[0126] The preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art having ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims.

[0127] According to a pouch forming device related to one embodiment of the present invention, a cup portion can be formed by first stretching a pre-forming area of ​​a pouch sheet and then secondly stretching the first-stretched pre-forming area.

Claims

1. In a pouch forming device for forming a cup part in a pre-forming area of ​​a pouch sheet, A first die section having a mold opening and configured to have the pouch sheet placed thereon so that the preforming area covers the mold opening; A first pressurizing portion for fixing the above pouch sheet to the first die portion; and A stretching unit including a first stretching member configured to pressurize a central region of the preformed region of the pouch sheet, and a second stretching member configured to pressurize a first edge region surrounding the central region, A pouch forming device wherein the first and second elongation members are arranged to press the central region and the first edge region, respectively, along different directions toward the mold opening.

2. In paragraph 1, The above second extension member is arranged to simultaneously pressurize a plurality of first points along the circumferential direction of the first edge region, The above second extension member is a pouch forming device in which the plurality of first points are spaced apart from the central region at a predetermined interval.

3. In paragraph 2, A pouch forming device in which the second extension member is arranged such that a virtual first line connecting the plurality of first points forms a closed curve.

4. In paragraph 2, A pouch forming device in which the second extension member is provided so that the virtual first line connecting the plurality of first points has a circular shape having a radius larger than the central area.

5. In paragraph 2, The above second extension member is a pouch forming device in which a virtual first line connecting the plurality of first points has a polygonal shape.

6. In paragraph 1, The above-mentioned extension member further includes a third extension member configured to pressurize a second edge region surrounding the first edge region, A pouch forming device wherein the second elongation member and the third elongation member are arranged to press the first edge region and the second edge region respectively along different directions toward the mold opening.

7. In paragraph 6, A pouch forming device in which the third extension member is configured to simultaneously pressurize a plurality of second points along the circumferential direction of the second edge region.

8. In paragraph 7, The third extension member is a pouch forming device in which a virtual second line connecting the plurality of second points forms a closed curve.

9. In paragraph 7, A pouch forming device in which the third extension member is provided such that a virtual second line connecting the plurality of second points has a circular shape having a radius larger than that of the first edge area.

10. In paragraph 7, The above third extension member is a pouch forming device in which a virtual second line connecting the plurality of second points is provided to have a polygonal shape.

11. In paragraph 6, It additionally includes a control unit configured to control the movement of the first to third extension members, A pouch forming device in which the above control unit is arranged to simultaneously pressurize the first and third elongation members in the preforming region.

12. In paragraph 11, A pouch forming device in which the above control unit is arranged to simultaneously pressurize the first to third elongation members in the preforming region.

13. In paragraph 6, A pouch forming device in which the first to third extension members are formed as curved portions in a portion that comes into contact with the preforming area.

14. In paragraph 6, A pouch forming device having balls rotatably positioned in a portion that contacts the preforming area, the first to third elongation members.

15. In paragraph 1, A second die section having a mold groove in which the pre-molded area, which has been formed through the above-mentioned extension section, is settled; A second pressurizing portion for fixing the pouch sheet mounted on the second die; and A pouch forming device comprising a punching block configured to be inserted into the mold groove, and further comprising a punching section configured to extend the pre-forming region into the mold groove.

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