Bag forming equipment

Abstract

According to an embodiment of the present disclosure, a bag forming device includes: a mold unit having a forming groove formed in a portion where a bag film is set; a partition plate that divides the forming groove into at least two parts; and a pressing unit that presses the bag film set on the mold unit to form an electrode assembly accommodating portion, wherein a chamfered portion is formed at a lower end portion of the partition plate.

Description

Technical Field

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of Korean Patent Application No. 10-2020-0164148 filed in the Korean Intellectual Property Office on November 30, 2020, the disclosure of which is incorporated herein by reference in its entirety.

[0003] The present disclosure relates to a bag forming apparatus, and more particularly, to a bag forming apparatus having improved durability. Background Art

[0004] With the recent rapid increase in demand for portable electronic products such as notebooks, video cameras, and portable phones and the in-depth development of electric vehicles, energy storage batteries, robots, satellites, etc., much research is being conducted on secondary batteries used as driving power sources.

[0005] The electrode assembly installed in the battery housing is an electric power generating element capable of charging and discharging, which has a positive electrode / separator / negative electrode stacking structure, and the electrode assembly is divided into a jelly roll type, a stacking type, and a stacking / folding type. The jelly roll type electrode assembly is configured to have a structure in which a long sheet type positive electrode and a long sheet type negative electrode applied with active materials are wound with a separator interposed between the positive electrode and the negative electrode, the stacking type electrode assembly is configured to have a structure in which a large number of positive electrodes with a predetermined size and a large number of negative electrodes with a predetermined size are sequentially stacked with a separator interposed between the positive electrode and the negative electrode, and the stacking / folding type electrode assembly is a combination of a jelly roll type electrode assembly and a stacking type electrode assembly. Among them, the jelly roll type electrode assembly has the advantages of being easy to manufacture and having a high energy density per unit weight.

[0006] In addition, based on the shape of the battery case, secondary batteries are divided into cylindrical batteries in which the electrode assembly is built in a cylindrical metal can, prismatic batteries in which the electrode assembly is built in a prismatic metal can, and pouch batteries in which the electrode assembly is built in a pouch-type case formed of an aluminum laminate sheet.

[0007] The pouch-type secondary battery includes an electrode assembly in which electrodes and separators are alternately laminated, and a pouch case for accommodating the electrode assembly. The method for manufacturing the secondary battery includes: an electrode manufacturing step of manufacturing electrodes, an electrode assembly manufacturing step of alternately laminating electrodes and separators to manufacture the electrode assembly, an electrode lead bonding step of bonding electrode leads to the electrode assembly, and a pouch sealing step of accommodating the electrode assembly in the pouch case and sealing the edge surface of the pouch case in a state in which the ends of the electrode leads are led out to the outside.

[0008] Here, a bag shell is manufactured using a bag forming device, the bag forming device including: a mold unit in which a bag film is set and a forming groove is formed, and a pressing unit that inserts the bag film into the forming groove while pressing the bag film set on the mold unit, thereby forming an electrode assembly accommodating portion. Here, the forming groove is provided with a partition plate, and the partition plate divides the forming groove into two parts. In addition, the pressing unit is formed by a pair of pressing parts, and the pair of pressing parts are respectively inserted into the forming groove divided based on the partition plate.

[0009] This bag forming apparatus has a problem that a central portion of the bag film between a pair of pressing portions is also pressurized, wherein the pressure applied to the central portion of the bag film is transmitted to the partition plate as it is, and the partition plate is damaged or deformed.

[0010] Prior art literature

[0011] Patent Literature

[0012] Korean Unexamined Patent Publication No. 2013-0132093 Summary of the invention

[0013] Technical issues

[0014] It is an object of the present disclosure to provide a bag forming apparatus having improved durability.

[0015] However, the problems to be solved by the embodiments of the present disclosure are not limited to the above-mentioned problems, and various extensions can be made within the scope of the technical concept included in the present disclosure.

[0016] Technical Solution

[0017] According to an embodiment of the present disclosure, a bag forming device is provided, comprising: a mold unit having a forming groove formed in a portion where a bag film is set; a partition plate that divides the forming groove into at least two parts; and a pressing unit that presses the bag film set on the mold unit to form an electrode assembly accommodating portion, wherein a chamfered portion is formed at a lower end portion of the partition plate.

[0018] The lower end portion of the partition plate may be connected to the mold unit, and the chamfered portion may be formed at a portion where the mold unit is connected to the partition plate.

[0019] The partition plate and the mold unit may be integrally formed.

[0020] The partition plate may be connected to both wall surfaces of the forming groove.

[0021] The bag forming apparatus may further include a blank holder located between the pressing unit and the die unit.

[0022] The blank holder may fix the bag film to an upper end portion of the mold unit.

[0023] The blank holder may include a protrusion adjacent to a connection portion between the partition plate and the mold unit.

[0024] The end portion of the protruding portion of the blank holder has a structure that is inclined corresponding to the chamfered portion formed at the lower end portion of the partition plate.

[0025] The blank holder may include a first blank holder and a second blank holder respectively formed on left and right sides of the lower end portion of the partition plate.

[0026] The chamfered portion of the divider plate may include a first chamfered portion adjacent to the first blank holder and a second chamfered portion adjacent to the second blank holder.

[0027] Beneficial Effects

[0028] According to an embodiment of the present disclosure, a chamfer portion may be formed at a connection portion between a mold unit and a partition plate for partitioning a forming groove, thereby reducing cracks caused by vibration of the partition plate and collision with surrounding components.

[0029] Furthermore, a chamfered portion may be formed on a member corresponding to the chamfered portion of the partition plate, thereby further ensuring an allowable depth for bag forming and stably ensuring an actual forming depth.

[0030] The effects of the present disclosure are not limited to the above-mentioned effects, and additional other effects not described above will be clearly understood by those skilled in the art from the description of the appended claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 is an exploded perspective view showing a pouch-type battery cell;

[0032] Figure 2 is a diagram showing a bag forming apparatus according to an embodiment of the present disclosure;

[0033] Figure 3 It is shown in Figure 2 A perspective view of a die unit before a pressing unit of a bag forming apparatus moves;

[0034] Figure 4 is along Figure 3 A partial cross-sectional view taken along line AA;

[0035] Figure 5 It is a partial cross-sectional view according to a comparative example. DETAILED DESCRIPTION

[0036] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can implement them. The present disclosure can be modified in various ways and is not limited to the embodiments set forth herein.

[0037] For clarity, description of parts not related to the specification will be omitted herein, and the same reference numerals denote the same elements throughout the specification.

[0038] In addition, in the drawings, for the convenience of description, the size and thickness of each element are arbitrarily shown, and the present disclosure is not necessarily limited to those shown in the drawings. In the drawings, for the sake of clarity, the thickness of layers, regions, etc. are exaggerated. In the drawings, for the convenience of description, the thickness of some layers and regions is exaggerated.

[0039] In addition, it will be understood that when an element such as a layer, film, region, or plate is referred to as being "on" or "above" another element, the element may be directly on the other element or there may be intervening elements. Conversely, when an element is referred to as being "directly on" another element, it means that there are no intervening elements. In addition, the term "on..." or "above..." refers to being disposed on or below a reference portion, and does not necessarily mean being disposed at the upper end of the reference portion in the opposite direction of gravity.

[0040] Furthermore, throughout the description, when a part is referred to as “comprising” a certain component, it means that the part can further include other components, not excluding the other components, unless otherwise stated.

[0041] Furthermore, throughout the description, when "plane" is mentioned, it means when the target portion is viewed from the upper side, and when "section" is mentioned, it means when the target portion is viewed from one side of the section cut vertically.

[0042] Figure 1 is an exploded perspective view showing a pouch-type battery cell.

[0043] Reference Figure 1 , the pouch-type battery cell 100 can be manufactured by accommodating the electrode assembly 200 in the cell housing 300 and then sealing the housing. The electrode assembly 200 may include a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. The electrode assembly 200 may be a stacked type electrode assembly, a jelly roll type electrode assembly, or a stacked / folded type electrode assembly.

[0044] Each of the positive electrode and the negative electrode includes an electrode tab 210t, and electrode leads 210 and 220 respectively connected to the electrode tabs 210t may be exposed to the outside of the unit case 300. The electrode tab 210t may be formed by extending the foil of the electrode sheet included in the electrode assembly 200. In addition, the electrode leads 210 and 220 may be respectively located in the sealing portion 300S in a state covered by the lead film 350, thereby ensuring sealing and insulation.

[0045] The unit case 300 is composed of a laminate sheet and may include a resin layer for heat fusion and a metal layer for preventing material penetration. The unit case 300 may include an upper case 310 and a lower case 320.

[0046] A concave receiving portion 300ST capable of seating the electrode assembly 200 may be formed in each of the upper case 310 and the lower case 320. Sealing portions 300S1 and 300S2 may be provided along the peripheries of the receiving portions 300ST of the upper case 310 and the lower case 320, respectively. The sealing portion 300S1 of the upper case 310 and the sealing portion 300S2 of the lower case 320 may be thermally fused to each other to form a sealing portion and seal the unit case 300.

[0047] In another embodiment of the present disclosure, one side of the upper shell and one side of the lower shell may be connected to each other as a whole, and the remaining three sides may be heat fused. In addition, the receiving portion 300ST may be formed only in any one of the upper shell 310 and the lower shell 320, and the other shell may have a planar shape.

[0048] The cell case 300 may include a resin layer, a metal layer, a packaging sheet layer, etc. to protect the pouch-type secondary battery, and a process of forming a pouch film is required for this purpose.

[0049] Figure 2 is a diagram illustrating a bag forming apparatus according to an embodiment of the present disclosure. Figure 3 It is shown in Figure 2 A perspective view of the mold unit before the pressing unit of the bag forming apparatus moves.

[0050] Reference Figure 2 and Figure 3 , the bag forming apparatus 1000 according to the present embodiment includes: a mold unit 500 having a forming groove formed in a portion where a bag film 510 is provided; a partition plate 570 that divides the forming groove 500a into at least two parts; and a pressing unit 400 that presses the bag film 510 provided on the mold unit 500 to form an electrode assembly receiving portion. At this time, the partition plate 570 is connected to two wall surfaces 500w of the forming groove 500a corresponding to each other, and can divide the forming groove 500a into two parts. The mold unit 500 according to the present embodiment may be provided on a substrate 700.

[0051] In the mold unit 500 , when both surfaces of the bag film 510 are pressed to be formed into the forming groove 500 a with reference to the partition plate 570 , a pair of electrode assembly receiving parts may be formed with reference to the center of the bag film 510 where the partition plate 570 is located.

[0052] The pressing unit 400 is used to press the bag film 510 located in the forming groove 500a to form the electrode assembly receiving portion, and is disposed on the mold unit 500. The pressing unit 400 includes: a moving part 420 disposed to be able to descend toward the mold unit 500; a demolding member 430 disposed at the lower part of the moving part 420; and a pressing part 440 disposed at the lower part of the demolding member 430.

[0053] When the bag film 510 is placed on the upper surface of the mold unit 500, the demolding member 430 according to this embodiment descends, and when the lower surface of the demolding member 430 contacts the upper surface of the bag film 510, the demolding member 430 and the mold unit 500 may abut each other via the bag film 510. At this time, the demolding member 430 may press the bag film 510 from above to fix it, and when the electrode assembly receiving part is formed by uniformly pressing the bag film 510, the tensile force applied to the bag film 510 may be uniformly distributed.

[0054] The pressing part 440 according to the present embodiment may be inserted into the forming groove 500 a in a state of pressing the bag film 510 located in the forming groove 500 a , and may form the electrode assembly receiving part on the bag film 510 .

[0055] The pressing parts 440 are respectively disposed on both sides of the lower portion of the moving part 420 based on the partition plate 570 , thereby forming electrode assembly receiving parts on both sides of the bag film 510 based on the partition plate 570 .

[0056] At this time, the pressing force of the pressing unit 400 is transmitted to the partition plate 570 via the bag film 510 , and thus the partition plate 570 may be damaged or deformed.

[0057] Hereinafter, a method for preventing damage to the partition plate 570 and improving bag forming efficiency according to an embodiment of the present disclosure will be described in comparison with a comparative example.

[0058] Figure 4 is along Figure 3 A partial cross-sectional view taken along line AA. Figure 5 It is a partial cross-sectional view according to a comparative example.

[0059] Reference Figure 4, a chamfered portion 570cp is formed at the lower end portion of the partition plate 570 according to the present embodiment. The chamfered portion 570cp may have a shape in which the corner is not formed at a right angle but is chamfered. The lower end portion of the partition plate 570 is connected to the mold unit 500, and the chamfered portion 570cp may be formed at a portion where the mold unit 500 is connected to the partition plate 570. At this time, the partition plate 570 and the mold unit 500 may be formed integrally.

[0060] According to the present embodiment, since the chamfered portion 570cp is formed at the lower end of the partition plate 570, the peripheral components of the partition plate 570, such as Figure 2 There is a risk that cracks may be generated in the partition plate 570 due to the pressing force of the pressing portion 440 .

[0061] Reference Figure 2 and Figure 4 The bag forming apparatus 1000 according to the present embodiment may further include a blank holder 590 located between the pressing unit 400 and the mold unit 500. The blank holder 590 may be a portion adjacent to the pressing portion 440, and when the electrode assembly receiving portion of the bag film 510 is formed by the pressing portion 440, cracks may be prevented from being generated at the corners of the receiving portion.

[0062] The blank holder 590 according to the present embodiment may include a protrusion 590p adjacent to the connection portion between the partition plate 570 and the mold unit 500. At this time, the end of the protrusion 590p of the blank holder 590 may have a structure inclined corresponding to the chamfered portion 570cp formed at the lower end of the partition plate 570. Due to the inclined structure of the blank holder 590 and the chamfered portion 570cp of the lower end of the partition plate 570 adjacent thereto, the area of ​​the portions adjacent to each other during pressing can be minimized, and the risk of cracks due to peripheral components when the partition plate 570 vibrates can be minimized. Figure 5 In the comparative example, since the connection portion between the partition plate 57 and the mold unit 50 connected to the lower end of the partition plate 57 has a right-angle structure, the impact load generated by the proximity to the blank holder 59 is large, and there is a concern that the bag forming equipment may be damaged.

[0063] In addition, due to the inclined structure of the chamfered portion 570cp and the protrusion 590p of the blank holder 590, the allowable depth for sufficiently ensuring the forming depth is greater than Figure 5Comparative example. According to the present embodiment, the actual forming depth can be stably ensured by additionally ensuring the allowable depth for bag forming. The expected forming depth may not be formed due to the material properties of the bag film and the tool of the bag forming equipment, and thus the lower end of the tool may be lifted by the sub-motor, and cracks may be generated in the tool due to the impact generated at this time. Therefore, according to the present embodiment, when the allowable depth for bag forming is additionally ensured, the impact can be alleviated.

[0064] The blank holder 590 according to the present embodiment may include a first blank holder 590a and a second blank holder 590b respectively formed on the left and right sides of the lower end portion of the partition plate 570. The chamfered portion 570cp of the partition plate 570 may include a first chamfered portion adjacent to the first blank holder 590a and a second chamfered portion adjacent to the second blank holder 590b.

[0065] Although the present invention has been shown and described above with reference to preferred embodiments, the scope of the present disclosure is not limited thereto, and many other modifications and improvements designed by those skilled in the art using the basic principles of the invention described in the appended claims fall within the spirit and scope of the present disclosure.

[0066] Reference Symbol Description

[0067] 400: Pressing unit

[0068] 440: Pressing part

[0069] 500: Mould unit

[0070] 500a: Forming groove

[0071] 510: Bag film

[0072] 570: Divider

[0073] 570cp: Chamfer

[0074] 590: Blank holder.

Claims

1. A bag forming device comprising: a die unit having a forming groove formed in a portion where the bag film is disposed; a partition plate dividing the forming groove into at least two parts; and a pressing unit that presses the bag film disposed on the mold unit to form an electrode assembly receiving portion, A chamfered portion is formed at the lower end of the partition plate. wherein the bag forming apparatus further comprises a blank holder located between the pressing unit and the die unit, wherein the blank holder fixes the bag film to the upper end of the mold unit, wherein the blank holder comprises a protrusion adjacent to a connection between the partition plate and the die unit, and The end of the protruding portion of the blank holder has a structure that is inclined corresponding to the chamfered portion formed at the lower end of the partition plate.

2. The bag forming apparatus according to claim 1, wherein: The lower end portion of the partition plate is connected to the mold unit, and the chamfered portion is formed at a portion where the mold unit is connected to the partition plate.

3. The bag forming apparatus according to claim 2, wherein: The partition plate and the mold unit are integrally formed.

4. The bag forming apparatus of claim 1, wherein: The partition plate is connected to both wall surfaces of the forming groove.

5. The bag forming apparatus of claim 1, wherein: The blank holder includes a first blank holder and a second blank holder respectively formed on the left and right sides of the lower end portion of the partition plate.

6. The bag forming apparatus of claim 5, wherein: The chamfered portion of the partition plate includes a first chamfered portion adjacent to the first blank holder and a second chamfered portion adjacent to the second blank holder.

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