Pouch manufacturing equipment

Abstract

The present invention relates to a pouch manufacturing apparatus, comprising: a lower die having a forming groove for forming a cup portion in a pouch film; an upper die arranged spaced above the lower die; and a punch supported by the upper die and arranged to move toward the forming groove to pressurize the pouch film arranged on the lower die, the punch comprising: an upper punch connected to the upper die so as to be vertically movable; a lower punch arranged spaced below the upper punch and arranged to move together with the upper punch to pressurize the pouch film; and an elastic portion arranged between the upper punch and the lower punch to elastically support the lower punch.

Description

Technical Field

[0001] This application claims the benefit of priority based on Korean Patent Application No. 10-2021-0117120 filed on September 2, 2021, and all the contents disclosed in the Korean Patent Application are incorporated herein by reference in their entirety.

[0002] The present invention relates to a pouch manufacturing apparatus.

Background Art

[0003] Generally, a secondary battery means a battery that can be charged and discharged, unlike a primary battery that cannot be charged, and is widely used in electronic devices such as mobile phones, laptop computers, camcorders, or electric vehicles. In particular, lithium secondary batteries have a larger capacity than nickel-cadmium batteries or nickel-metal hydride batteries and a high energy density per unit weight, so the degree of their utilization is rapidly increasing.

[0004] Secondary batteries may also be classified according to the structure of the electrode assembly having a positive electrode / separator / negative electrode structure. Typically, a jelly roll electrode assembly having a structure in which a long sheet-like electrode is wound with a separator interposed therebetween, a stack-type electrode assembly in which a large number of electrodes cut out in a predetermined size unit are sequentially stacked with a separator interposed therebetween, a bi-cell or full-cell in which electrodes of a predetermined unit are stacked with a separator interposed therebetween, and a stack / folding-type electrode assembly having a structure in which the stack / folding-type electrode assembly is wound, etc. may be mentioned.

[0005] And secondary batteries can also be classified into cylindrical batteries and prismatic batteries in which the electrode assembly is built into a cylindrical or prismatic metal can according to the shape of the battery case, and pouch-type batteries in which the electrode assembly is built into a pouch-type case made of an aluminum laminate sheet, etc.

[0006] Figure 1 shows an example of a pouch-type secondary battery. The pouch-type secondary battery 1 includes an electrode assembly 20 formed by alternately stacking electrodes and a separator membrane, and a pouch 10 into which the electrode assembly is inserted. The pouch includes a cup portion 11 of the pouch, which has a curved shape so as to directly accommodate the electrode assembly. The cup portion of the pouch may be provided by a cup portion 11L on the left side of the pouch and a cup portion 11R on the right side of the pouch so as to surround the electrode assembly on both sides. A peripheral portion 14 of the pouch is formed around the cup portion of the pouch, which is sealed to seal the pouch from the outside.

[0007] The cup portion of a pouch is typically formed by pressing the pouch film with a punch. However, impacts can occur during this pressing process, affecting the punch and other components. Such impacts can negatively affect the appearance of the pouch and the lifespan of the pouch manufacturing equipment, so it is preferable to effectively cushion these impacts. [Overview of the Initiative] [Problems that the invention aims to solve]

[0008] The object of the present invention is to provide a pouch manufacturing apparatus that can effectively mitigate the impact applied to the punch when the pouch film is pressed by the punch, and the impact applied to members that come into direct or indirect contact with the punch.

[0009] Furthermore, an object of the present invention is to provide a pouch manufacturing apparatus that can further improve the appearance of the pouch.

[0010] Furthermore, an object of the present invention is to provide a pouch manufacturing apparatus that can further shape the cup portion of the pouch to be more angular, and can further shape the depth of the cup portion to be more consistent. [Means for solving the problem]

[0011] In one example, the pouch manufacturing apparatus includes a lower die having a forming groove for forming a cup portion in a pouch film, an upper die positioned above and spaced apart from the lower die, and a punch supported by the upper die and configured to move toward the forming groove to pressurize the pouch film positioned on the lower die, wherein the punch may include an upper punch connected to the upper die so as to be vertically movable, a lower punch positioned below and spaced apart from the upper punch and configured to move together with the upper punch to pressurize the pouch film, and an elastic portion positioned between the upper punch and the lower punch to elastically support the lower punch.

[0012] In other examples, the elastic portion may be provided to elastically press the lower punch downwards.

[0013] In yet another example, the elastic portion may include a connecting bar fixed to either the upper punch or the lower punch, and connected to the other of the upper punch and the other so as to be vertically movable relative to the other, and an elastic member provided between the upper punch and the lower punch so as to surround the connecting bar.

[0014] In yet another example, the upper punch may include an upper punch body that forms the outer shape of the upper punch, a first through-hole that penetrates the upper punch body from the upper surface of the upper punch body to a point between the upper and lower surfaces of the upper punch body, and a second through-hole with a larger inner diameter than the first through-hole, that penetrates the upper punch body from the point to the lower surface of the upper punch body and communicates with the first through-hole.

[0015] In yet another example, the connecting bar may include a head positioned outside the upper surface of the upper punch body, and a fixing bar extending downward from the head, passing through the first and second through holes, and fixed at its lower end to the lower punch.

[0016] In yet another example, the head may be formed with a diameter larger than the first through-hole so as not to be inserted into the first through-hole, or with a diameter larger than the central hole of a washer positioned between the head and the upper surface of the upper punch body.

[0017] In yet another example, the upper end of the elastic member can be inserted into the second through-hole so as to be secured to the stepped portion formed by the difference in inner diameter between the first through-hole and the second through-hole.

[0018] In yet another example, the upper punch includes an upper punch body that forms the outer shape of the upper punch, and a through groove that penetrates the upper punch body from a point between the upper and lower surfaces of the upper punch body to the lower surface of the upper punch body, the connecting bar includes a head disposed inside the through groove, and a fixing bar formed with a smaller diameter than the head and extending downward from the head and fixed at its lower end to the lower punch, the upper end of the elastic member can be inserted into the through groove so as to be located below the head.

[0019] In yet another example, the elastic portion includes a main body portion that is inserted into the through groove of the upper punch body and has an inverted U-shaped cross-section, and an extension portion that extends horizontally outward from the lower end of the main body portion and is in close contact with the lower surface of the upper punch body, and the connecting bar and the elastic member can be inserted into the internal space of the main body portion that is inserted into the through groove.

[0020] In yet another example, the elastic portion may include an outer elastic member positioned adjacent to the outer edge of the lower punch, and an inner elastic member positioned more adjacent to the center of the lower punch than the outer elastic member.

[0021] In other examples, the elastic modulus of the outer elastic member may be lower than that of the inner elastic member.

[0022] In still other examples, the lower die may include a lower die body that forms the outer shape of the lower die and in which the forming groove is formed, and a nest that is disposed movably in the vertical direction inside the forming groove and is provided to support the punch moved into the forming groove.

[0023] In still other examples, the punch may be provided to move downward until the pouch film is in close contact with the upper surface of the nest.

Advantages of the Invention

[0024] According to the present invention, since the punch for pressing the pouch film includes an upper punch and a lower punch that are separated from each other, and an elastic part disposed therebetween, the impact applied to the punch during pressing by the punch, and the impact applied to a member that directly or indirectly contacts the punch can be effectively alleviated.

[0025] Also, according to the present invention, even when a nest is applied to the pouch manufacturing apparatus, an elastic member for buffering is provided in the punch rather than in the nest, so that the appearance of the pouch can be formed better than when an elastic member is provided in the nest.

[0026] Furthermore, according to the present invention, a vacuum stretching process can be applied to the pouch manufacturing apparatus. When the vacuum stretching process is applied, the cup portion of the pouch can be formed to be more angular by the vacuum action and the punch pressing, and the depth of the cup portion can be formed to be more constant.

Brief Description of the Drawings

[0027] [Figure 1] It is an exploded perspective view showing a secondary battery pouch and an electrode assembly built therein. [Figure 2] It is a cross-sectional view showing a pouch manufacturing apparatus according to Embodiment 1 of the present invention. [Figure 3] It is a cross-sectional view showing a punch applied to the pouch manufacturing apparatus of FIG. 2. [Figure 4] This diagram illustrates the process of forming pouch film using the pouch manufacturing apparatus shown in Figure 2. [Figure 5] This diagram illustrates the process of forming pouch film using the pouch manufacturing apparatus shown in Figure 2. [Figure 6] This diagram illustrates the process of forming pouch film using the pouch manufacturing apparatus shown in Figure 2. [Figure 7] This diagram illustrates the process of forming pouch film using the pouch manufacturing apparatus shown in Figure 2. [Figure 8] This diagram illustrates the process of forming pouch film using the pouch manufacturing apparatus shown in Figure 2. [Figure 9] This is a cross-sectional view showing a pouch manufacturing apparatus according to Embodiment 2 of the present invention. [Figure 10] This is a cross-sectional view showing a punch applied to the pouch manufacturing apparatus shown in Figure 9. [Figure 11] This is a rear view of the punch in Figure 10 after the lower punch has been removed. [Best Mode for Carrying Out the Invention]

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings, so that they can be easily implemented by a person with ordinary skill in the art to which the present invention pertains. However, the present invention can be realized in a variety of different forms and is not limited or restricted by the following embodiments.

[0029] To clearly describe the present invention, detailed descriptions of relevant prior art that are irrelevant to the description or that could unnecessarily obscure the gist of the invention have been omitted. In this specification, when assigning reference numerals to components in the drawings, the same or similar reference numerals are used throughout the specification for components that are the same or similar.

[0030] Furthermore, terms and words used in this specification and in the claims should not be interpreted in a manner limited to their ordinary or dictionary meanings, but rather in a manner consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors may appropriately define the concepts of terms in order to best describe their invention.

[0031] Embodiment 1 Figure 2 is a cross-sectional view showing a pouch manufacturing apparatus according to Embodiment 1 of the present invention. The pouch manufacturing apparatus 100 according to Embodiment 1 of the present invention includes a lower die 110, an upper die 120, and a punch 130, as shown in Figure 2.

[0032] The lower die 110 may be a die in which a forming groove 111 is formed for forming the cup portion 11 (see Figure 1). The forming groove 111 may be a groove or hole formed by curving downward on the upper surface 112U of the lower die body 112 which forms the outer shape of the lower die 110. The pouch film F (see Figure 4) placed on the upper surface 112U of the lower die body 112 can be pressed downward on the forming groove 111 by a punch 130, which will be described later, for the formation of the cup portion 11.

[0033] The upper die 120 may be a die positioned above the lower die 110. A connecting column B may be provided between the upper die 120 and the lower die 110 to maintain the separation distance. Cylinders 161 and 166 may be provided on the upper die 120 for the vertical movement of the punch 130 or the vertical movement of the stripper 150, which will be described later.

[0034] The punch 130 may be a block for pressurizing the pouch film F positioned on the lower die 110. The punch 130 may be supported by the upper die 120. The punch 130 may be configured to move toward the forming groove 111. For example, the punch 130 may be indirectly fixed to the upper die 120 by being connected to a punch cylinder 161 fixed to the upper die 120, and may move vertically relative to the upper die 120 in response to the operation of the punch cylinder 161. The punch cylinder 161 may include a cylinder body 162 and a cylinder rod 163 that reciprocates by hydraulic pressure supplied inside the cylinder body 162. The punch 130 may be connected to the cylinder rod 163.

[0035] The punch 130 may include an upper punch 131. The upper punch 131 may be a block that is vertically movable and connected to the upper die 120. The cylinder rod 163 of the punch cylinder 161 may be connected to the upper punch 131. The upper punch 131 may include an upper block 132 positioned on the upper side and a lower block 133 positioned on the lower side and formed wider in the left-right direction than the upper block 132 with respect to Figure 2. The upper punch 131 may have an inverted T-shaped cross-section.

[0036] The punch 130 may include a lower punch 136. The lower punch 136 may be a block positioned below and separated from the upper punch 131. The lower punch 136 can move together with the upper punch 131 in accordance with the movement of the upper punch 131. During such movement, the lower punch 136 can contact the pouch film F and pressurize the pouch film F (see Figure 7). The lower punch 136 can be connected to the upper punch 131 by a predetermined bar and move together with the upper punch 131 while separated from it. For example, the lower punch 136 can be connected to the upper punch 131 at a distance by a fixed bar 143 (see Figure 3), which will be described later.

[0037] The punch 130 may include an elastic portion 140 that elastically supports the lower punch 136 relative to the upper punch 131. For example, if the lower punch 136 is pressed upward by a nest 113 or the like (described later) while the lower punch 136 is pressing down on the pouch film F, the elastic portion 140 can mitigate the impact applied to the lower punch 136 while compressing an elastic member 146 (see Figure 3) (see Figure 7).

[0038] The elastic portion 140 can be provided to elastically press down on the lower punch 136 while being supported by the upper punch 131 for cushioning purposes. For example, the elastic member 146 of the elastic portion 140 may be positioned between the upper punch 131 and the lower punch 136 in a compressed state. The amount of compression of the elastic member 146 may be determined according to the required amount of cushioning.

[0039] The elastic portion 140 can be positioned between the upper punch 131 and the lower punch 136. For example, all or part of the elastic portion 140 may be positioned between the upper punch 131 and the lower punch 136. Figure 2 illustrates a case where part of the elastic portion 140 is positioned between the upper punch 131 and the lower punch 136.

[0040] The pouch manufacturing apparatus 100 according to Embodiment 1 of the present invention includes an upper punch 131 and a lower punch 136 that pressurize the pouch film F, and an elastic part 140 positioned between them. Therefore, it is possible to effectively mitigate the impact applied to the punch 130 during pressurization by the punch 130, and the impact applied to members (e.g., the nest 113 described later) that come into direct or indirect contact with the punch 130.

[0041] The elastic portion 140 of this embodiment will be described in detail with reference to Figure 3. Figure 3 is a cross-sectional view showing a punch applied to the pouch manufacturing apparatus of Figure 2. The elastic portion 140 may include a connecting bar 141 and an elastic member 146, as shown in Figure 3.

[0042] The connecting bar 141 may be fixed to either the upper punch 131 or the lower punch 136, and may be a bar that is connected to the other of the upper punch 131 or lower punch 136 so as to be movable in the vertical direction. Figure 3 illustrates a connecting bar 141 that is fixed to the lower punch 136 and movably connected to the upper punch 131.

[0043] In Figure 3, when the upper punch 131 moves vertically, the lower punch 136, which is connected to the upper punch 131 by the connecting bar 141, can also move vertically together with the upper punch 131. In Figure 3, when the lower punch 136 moves upward due to an external force, only the connecting bar 141 fixed to the lower punch 136 can move upward together with the lower punch 136 without the upper punch 131 moving. At this time, the elastic member 146 can be compressed, and during such compression, the elastic member 146 can elastically support the lower punch 136. This makes it possible to mitigate the impact applied to the lower punch 136 and the like.

[0044] The connecting bar 141 may include a head 142 and a fixing bar 143 to achieve both vertically movable connection to the upper punch 131 and fixed to the lower punch 136.

[0045] The upper punch 131 may include an upper punch body 134 (including an upper block 132 and a lower block 133) that forms the outer shape of the upper punch 131, but the head 142 may be positioned outside the upper surface 134U of the upper punch body 134. The head 142 may be formed with a diameter larger than the through hole 135 (e.g., the first through hole 135a described later) so that it is not inserted into the through hole 135. A washer W may be placed between the head 142 and the upper surface 134U of the upper punch body 134, in which case the head 142 may be formed with a diameter larger than the central hole of the washer W through which the fixing bar 143 described later passes.

[0046] The upper punch 131 may include a through hole 135 (e.g., a first through hole 135a and a second through hole 135b described later) that penetrates the upper punch body 134 from the upper surface 134U to the lower surface 134L of the upper punch body 134, but the fixing bar 143 may be provided so as to extend downward from the head 142 and pass through the through hole 135. The lower end of the fixing bar 143 that is exposed on the lower side of the upper punch body 134 may be fixed to the lower punch 136. Figure 3 illustrates a lower end of the fixing bar 143 that is formed to a point, but the pointed lower end of the fixing bar 143 may have threads formed for screw connection with the lower punch 136.

[0047] The elastic member 146 is for forming the elastic force of the elastic part 140 and may be, for example, a spring. All or part of the elastic member 146 may be positioned between the upper punch 131 and the lower punch 136. Figure 3 illustrates a case where part of the elastic member 146 is inserted into the second through hole 135b, which will be described later, and the rest of the elastic member 146 is positioned between the upper punch 131 and the lower punch 136. The elastic member 146 may be provided so as to surround the connecting bar 141, as shown in Figure 3. When the elastic member 146 is positioned to surround the connecting bar 141, the elastic member 146 can support the lower punch 136 more stably during the relative movement of the lower punch 136 with respect to the upper punch 131. However, the elastic member may also be positioned separately from the connecting bar.

[0048] The elastic member 146 may be positioned to be fixed to the second through hole 135b of the two through holes 135a and 135b formed in the upper punch body 134. The first through hole 135a may be a hole that penetrates the upper punch body 134 from the upper surface 134U of the upper punch body 134 to a point P between the upper surface 134U and the lower surface 134L of the upper punch body 134. The second through hole 135b may be formed with a larger inner diameter than the first through hole 135a and penetrate the upper punch body 134 from the point P to the lower surface 134L of the upper punch body 134. The first through hole 135a and the second through hole 135b can communicate with each other. Since the inner diameters of the first through hole 135a and the second through hole 135b are different, a stepped portion 135c can be formed at the boundary between the first through hole 135a and the second through hole 135b. The upper end of the elastic member 146 is inserted into the second through hole 135b and can be securely attached to the stepped portion 135c between the first and second through holes 135a and 135b. This allows the elastic member 146 to be stably positioned between the upper punch 131 and the lower punch 136.

[0049] The pouch manufacturing apparatus 100 of this embodiment may include a stripper 150 for pressurizing and fixing the pouch film F, as shown in Figure 2. The stripper 150 is indirectly fixed to the upper die 120 by being connected to a stripper cylinder 166 fixed to the upper die 120, and can move vertically relative to the upper die 120 in response to the operation of the stripper cylinder 166. The stripper cylinder 166 may include a cylinder body 167 and a cylinder rod 168 that reciprocates in response to hydraulic pressure supplied inside the cylinder body 167. The stripper 150 may be connected to the cylinder rod 168. The punch 130 can move vertically through the stripper 150 via a hole H formed in the central part of the stripper 150.

[0050] The lower die 110 of this embodiment may include a lower die body 112 and a nest 113, as shown in Figure 2. The lower die body 112 may be a block that forms the outer shape of the lower die 110. A forming groove 111 may be formed in the lower die body 112 by recessing inward. The nest 113 may be provided inside the forming groove 111 to support a punch 130 that has moved into the forming groove 111. The punch 130 may be provided to move vertically inside the forming groove 111 in order to change its support position in accordance with the degree to which the punch 130 is inserted inside the forming groove 111. For this purpose, the lower die 110 may be provided with a nest cylinder 170 for the vertical movement of the nest 113.

[0051] The following describes the process of forming the pouch film F using the pouch manufacturing apparatus 100 of this embodiment, with reference to Figures 4 to 8. Figures 4 to 8 are diagrams illustrating the process of forming the pouch film using the pouch manufacturing apparatus shown in Figure 2.

[0052] First, as shown in Figure 4, the nest 113 moves downward. The distance the nest 113 moves can be determined based on the insertion depth of the punch 130. Figure 4 illustrates the case where the nest 113, which was located adjacent to the upper opening of the forming groove 111, moves downward. If the nest 113 is located adjacent to the lower bottom of the forming groove 111, the nest 113 can also move upward.

[0053] Next, as shown in Figure 5, the stripper 150 is lowered by the stripper cylinder 166. The stripper 150 can fix the pouch film F during molding by applying pressure to the pouch film F located on the upper surface 112U of the lower die body 112.

[0054] Next, as shown in Figure 6, the air inside the forming groove 111 is discharged through the vacuum passage 114 formed in the lower die body 112. This allows the pouch film F, positioned on the upper surface 112U of the lower die body 112, to be stretched downwards. For this vacuum stretching, the vacuum passage 114 of the lower die body 112 can be connected to a vacuum pump (not shown).

[0055] The pouch manufacturing apparatus 100 of this embodiment can also be applied to a vacuum stretching process. When the vacuum stretching process is applied, the cup portion 11 of the pouch can be made more angular, for example, the angle between the bottom surface and the side surface of the cup portion 11 can be made close to 90 degrees. An angular pouch can increase the volume of the electrode assembly housed in the same volume, thereby improving the energy density of the battery. Furthermore, when the vacuum stretching process is applied, the depth of the cup portion 11 in the manufactured pouch can be made to be approximately constant.

[0056] On the other hand, it is possible to consider placing an elastic member at the bottom of the nest 113 for cushioning. However, if an elastic member is placed at the bottom of the nest 113, the pouch film F may get caught between the inner wall of the lower die body 112 that defines the forming groove 111 and the nest 113 due to the vibration of the nest 113 during vacuum stretching or while the nest 113 is moving. This is undesirable because it spoils the appearance of the pouch. However, in the pouch manufacturing apparatus 100 of this embodiment, the elastic member 146 for cushioning is not placed in the nest 113 but in the punch 130, so the above problem does not occur.

[0057] Next, as shown in Figure 7, the punch 130 is lowered by the punch cylinder 161. This pressurizes the pouch film F, allowing the cup portion 11 of the pouch to be formed to be more angular. At this time, the impact between the punch 130 and the nest 113 can be mitigated by the elastic portion 140 of the punch 130. For example, when the punch 130 is impacted by the nest 113, as shown in Figure 7, the lower punch 136 moves toward the upper punch 131 while being elastically supported by the elastic portion 140, and the impact between the punch 130 and the nest 113 in this process can be mitigated. This can be beneficial for the excellent appearance of the pouch and the lifespan of the pouch manufacturing equipment.

[0058] On the other hand, the punch 130 may be configured to move downward until the pouch film F is in close contact with the upper surface of the nest 113. When moved in this manner, the pouch film F can be pressurized without any gap (excluding gaps caused by the film) being formed between the punch 130 and the nest 113, thereby allowing for a more favorable appearance of the pouch.

[0059] Finally, as shown in Figure 8, the punch cylinder 161 raises the punch 130.

[0060] Embodiment 2 Figure 9 is a cross-sectional view showing a pouch manufacturing apparatus according to Embodiment 2 of the present invention, Figure 10 is a cross-sectional view showing a punch applied to the pouch manufacturing apparatus of Figure 9, and Figure 11 is a rear view of the punch in Figure 10 after the lower punch has been removed. The manufacturing apparatus of Embodiment 2 differs from the manufacturing apparatus of Embodiment 1 in terms of the punch. The following description will focus on the punch 230. For reference, the matters described in Embodiment 1 can be applied identically or similarly to Embodiment 2.

[0061] A pouch manufacturing apparatus 200 according to Embodiment 2 of the present invention includes a lower die 110, an upper die 120, and a punch 230, as shown in Figure 9. The lower die 110 may include a forming groove 111. The lower die 110 may include a nest 113 positioned in the forming groove 111. The punch 230 may include an upper punch 231 and a lower punch 236. The upper punch 231 may include an upper block 232 and a lower block 233.

[0062] The pouch manufacturing apparatus 200 of this embodiment may include a stripper 150 for fixing the pouch film.

[0063] The punch 230 of this embodiment may include an elastic portion 240. The elastic portion 240 of this embodiment may include an outer elastic member 246o and an inner elastic member 246i, as shown in Figures 9 and 11. The outer elastic member 246o may be an elastic member positioned adjacent to the outer edge of the lower punch 236 (e.g., the four vertices of the lower punch with reference to Figure 11), and the inner elastic member 246i may be an elastic member positioned more adjacent to the center of the lower punch 236 than the outer elastic member 246o. Figure 11 shows, as an example, four outer elastic members 246o and four inner elastic members 246i. For reference, Figure 11 is a rear view of the punch 230 after the lower punch 236 has been removed, but the outer edge and center of the lower punch 236 can substantially correspond to the outer edge and center of the upper punch 231.

[0064] In this embodiment, the punch 230 is equipped with elastic members 246o and 246i adjacent to the outer edge of the lower punch 236 or the upper punch 231, and adjacent to the center of the lower punch 236 or the upper punch 231, respectively, so that the lower punch 236 can be supported even more stably via the elastic members 246o and 246i. For reference, connecting bars 241 and 241' (see Figure 10) can also be placed at the centers of the outer elastic member 246o and the inner elastic member 246i, similar to Embodiment 1.

[0065] In this embodiment, the elastic modulus of the outer elastic member 246o may be lower than that of the inner elastic member 246i. In this way, the central part of the region where the cup portion 11 is formed in the pouch film F (e.g., the region corresponding to the forming groove) is relatively strong, and the peripheral part is relatively weak, allowing the punch 230 to apply pressure accordingly. This can help suppress problems occurring at the corners of the cup portion 11 (the boundary between the bottom and the side) during the molding of the cup portion 11. For reference, even with materials having the same elastic modulus, the above effect can be achieved by varying the degree of compression (for example, by arranging the outer elastic member with a lower degree of compression).

[0066] On the other hand, the elastic portion 240o (hereinafter referred to as the outer elastic portion) positioned adjacent to the outer edge of the lower punch 236 and the elastic portion 240i (hereinafter referred to as the inner elastic portion) positioned adjacent to the center of the lower punch 236 relative to the outer elastic portion 240o may have different structures from each other, as shown in Figures 9 and 10.

[0067] The outer elastic portion 240o can have the same structure as the elastic portion 140 of Embodiment 1, as shown in Figure 10. That is, the outer elastic portion 240o can comprise a connecting bar 241 having a head 242 and a fixing bar 243, and an elastic member 246o. The outer elastic portion 240o can be positioned on the lower block 233 of the upper punch 231 having an inverted T-shaped cross-section.

[0068] The inner elastic portion 240i can be positioned in the region of the lower block 233 corresponding to the upper block 232, as shown in Figure 10. The inner elastic portion 240i may include a connecting bar 241' and an elastic member 246i. The connecting bar 241' may include a head 242' positioned inside a through groove 235' formed in the upper punch body 234. Here, the through groove 235' may be a groove formed to penetrate the upper punch body 234 from a point P' between the upper surface 234U and the lower surface 234L of the upper punch body 234 to the lower surface 234L of the upper punch body 234. The connecting bar 241' may include a fixing bar 243' formed with a smaller diameter than the head 242' and extending downward from the head 242' and fixed to the lower punch 236 at its lower end. The upper end of the elastic member 246i can be inserted into the through groove 235' so as to be positioned below the head 242'.

[0069] In the region of the upper punch 231 where the upper block 232 and the lower block 233 overlap, it is preferable that the inner elastic portion 240i is housed in the through groove 235' of the upper punch body 234, since the upper surface of the upper block 232 can contact the lower surface of the upper die 120, and the region of the upper punch 231 where the upper block 232 and the lower block 233 overlap is not only thicker than the lower block 233, but the upper surface of the upper block 232 can contact the lower surface of the upper die 120.

[0070] The inner elastic portion 240i may include a fixing member 247 that is inserted into and fixed in the through groove 235' of the upper punch body 234. The fixing member 247 may include a main body portion 247a that is inserted into the through groove 235' and has an inverted U-shaped cross-section, and an extension portion 247b that extends horizontally outward from the lower end of the main body portion 247a and is in close contact with the lower surface 234L of the upper punch body 234.

[0071] The connecting bar 241' and the elastic member 246i can be inserted into the internal space of the main body portion 247a, which is inserted into the through groove 235'. A stopper 247c that protrudes horizontally inward may be formed in the internal space of the main body portion 247a. The stopper 247c can prevent the head 242' of the connecting bar 241' from detaching downward. The stopper 247c can be spaced a predetermined distance below the ceiling surface of the internal space of the main body portion 247a in order to allow the connecting bar 241' to move up and down. The upper end of the elastic member 246i can be positioned below the stopper 247c.

[0072] With the fixing member 247 provided, the connecting bar 241' and the elastic member 246i can be placed on the fixing member 247 and then installed in the through groove 235' of the upper punch body 234, thus facilitating the installation of the inner elastic part 240i.

[0073] The above description is merely illustrative of the technical concept of the present invention, and any person with ordinary skill in the art to which the present invention belongs can make various modifications and alterations as long as they do not deviate from the essential characteristics of the present invention.

[0074] Therefore, the embodiments disclosed in this invention are for illustrative purposes only, and not to limit the technical concept of the invention, and the scope of the technical concept of the invention is not limited by such embodiments.

[0075] The scope of protection of this invention should be interpreted in accordance with the following claims, and all technical ideas within an equivalent scope should be interpreted as being included within the scope of the rights of this invention. [Explanation of Symbols]

[0076] 1. Pouch-type rechargeable battery 10 pouches 11, 11L, 11R Cup section 14 Peripheral area 20 Electrode assembly 100 Pouch Manufacturing Equipment 110 Lower die 111 Forming groove 112 Lower die body 112U top side 113 Nest 114 Vacuum passage 120 Top die 130 punches 131 Upper Punch 132 Upper block 133 Lower block 134 Upper punch body 134L lower surface 134U top surface 135 Through hole 135a 1st through hole 135b 2nd through hole 135c Step section 136 Lower punch 140 Elastic part 141 Connecting Bar 142 heads 143 Fixed bar 146 Elastic members 150 Strippers 161, 166 cylinders 162, 167 Cylinder body 163, 168 Cylinder rods 170 Nest Cylinder 200 Pouch Manufacturing Equipment 230 punches 231 Upper punch 232 Upper block 233 Lower block 234 Upper punch body 234L lower surface 234U top side 235' Through groove 236 Lower punch 240 Elastic part 240i Inner elastic part 240° Outer elastic part 241, 241' Connecting bar 242, 242' head 243, 243' Fixed bar 246i Inner elastic member 246o Outer elastic member 247 Fixing member 247a Main body part 247b Extension 247c Stopper

Claims

1. A lower die having forming grooves for forming the cup portion into the pouch film, An upper die is positioned above and separated from the lower die, Includes a punch supported by the upper die and positioned on the lower die, which is configured to move toward the forming groove to pressurize the pouch film, The aforementioned punch, An upper punch is connected to the upper die so as to be vertically movable, A lower punch is positioned below the upper punch and is provided to move together with the upper punch to pressurize the pouch film, It includes an elastic portion disposed between the upper punch and the lower punch, which elastically supports the lower punch, The aforementioned lower die is The lower die body forms the outer shape of the lower die and the forming groove is formed therein Includes a nest positioned to be vertically movable inside the forming groove and provided to support the punch as it is moved into the forming groove, The aforementioned punch, The pouch film is provided to move downward until it is in close contact with the upper surface of the nest. The nest is configured such that, before the punch presses the pouch film against the upper surface of the nest, the upper surface of the nest is positioned below the opening of the forming groove and the nest is positioned away from the bottom of the forming groove. A pouch manufacturing apparatus, wherein the lower die is configured to vacuum stretch the pouch film into the forming groove before the punch presses the pouch film into contact with the upper surface of the nest.

2. The elastic portion is The pouch manufacturing apparatus according to claim 1, wherein the lower punch is provided to elastically press downward.

3. The elastic portion is A connecting bar is fixed to either the upper punch or the lower punch, and is connected to the other of the upper punch and the lower punch so as to be movable in the vertical direction relative to the other. A pouch manufacturing apparatus according to claim 1, comprising an elastic member provided between the upper punch and the lower punch so as to surround the connecting bar.

4. The aforementioned upper punch, The upper punch body that forms the outer shape of the upper punch, A first through-hole extends through the upper punch body from the upper surface of the upper punch body to a point between the upper surface and the lower surface of the upper punch body, The pouch manufacturing apparatus according to claim 3, further comprising a second through-hole having an inner diameter larger than the first through-hole, penetrating the upper punch body from one point to the lower surface of the upper punch body, and communicating with the first through-hole.

5. The aforementioned connecting bar is A head positioned on the outside of the upper surface of the upper punch body, The pouch manufacturing apparatus according to claim 4, further comprising: a fixing bar extending downward from the head, passing through the first and second through holes, and fixed at its lower end to the lower punch.

6. The head is The pouch manufacturing apparatus according to claim 5, wherein the washer is formed with a diameter larger than the first through-hole so as not to be inserted into the first through-hole, or is formed with a diameter larger than the central hole of a washer disposed between the head and the upper surface of the upper punch body.

7. The upper end of the elastic member is The pouch manufacturing apparatus according to claim 4, wherein the second through-hole is inserted into the second through-hole so as to be securely attached to the stepped portion formed by the difference in inner diameter between the first through-hole and the second through-hole.

8. The aforementioned upper punch, The upper punch body that forms the outer shape of the upper punch, The upper punch body includes a through groove that penetrates the upper punch body from a point between the upper surface and the lower surface of the upper punch body to the lower surface of the upper punch body, The aforementioned connecting bar is A head positioned inside the aforementioned through groove, It includes a fixing bar that is formed with a smaller diameter than the head and extends downward from the head, with its lower end fixed to the lower punch, The upper end of the elastic member is The pouch manufacturing apparatus according to claim 3, wherein the head is inserted into the through groove so as to be located below the head.

9. The elastic portion is It includes a main body portion that is inserted into the through groove of the upper punch body and has an inverted U-shaped cross-section, and an extension portion that extends horizontally outward from the lower end of the main body portion and is in close contact with the lower surface of the upper punch body, The connecting bar and the elastic member are The pouch manufacturing apparatus according to claim 8, which is inserted into the internal space of the main body portion that is inserted into the through groove.

10. The elastic portion is An outer elastic member positioned adjacent to the outer edge of the lower punch, The pouch manufacturing apparatus according to claim 1, further comprising an inner elastic member positioned adjacent to the center of the lower punch from the outer elastic member.

11. The elastic modulus of the outer elastic member is, The pouch manufacturing apparatus according to claim 10, wherein the elastic modulus is lower than that of the inner elastic member.

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