Crimping apparatus of cylindrical battery

Abstract

The present invention provides a crimping apparatus configured to crimp a housing of a cylindrical battery, the crimping apparatus comprising: a punch configured to crimp the housing by pressing an upper portion of the housing; and a fixing unit including a punch insertion part configured to allow insertion of the punch, and a can support part configured to support at least a portion of the housing, form a stepped portion with the punch insertion part, and extend in one direction from the punch insertion part.

Description

Crimping device for cylindrical batteries

[0001] The present invention relates to a crimping device for a cylindrical battery. More specifically, the present invention relates to a crimping device for a cylindrical battery capable of minimizing damage to a cylindrical battery during the crimping process.

[0002] This application claims priority to Korean Patent Application No. 10-2023-0193315, filed on December 27, 2023, and all contents disclosed in the specification and drawings of the said application are incorporated by reference into this application.

[0003] This application claims priority to Korean Patent Application No. 10-2024-0015905, filed on February 1, 2024, and all contents disclosed in the specification and drawings of the said application are incorporated by reference into this application.

[0004] In general, secondary batteries are batteries that can be charged and discharged, unlike primary batteries that are not rechargeable. They are widely used as power sources for electronic devices such as mobile phones, laptop computers, and camcorders, as well as electric vehicles. In particular, lithium secondary batteries have an operating voltage of 3.6 V, which is about three times the capacity of nickel-cadmium batteries or nickel-hydrogen batteries, which are widely used as power sources for electronic devices. Due to their high energy density per unit weight, their utilization is rapidly increasing.

[0005] These lithium secondary batteries primarily use lithium oxide and carbon materials as the positive and negative active materials, respectively. Furthermore, lithium secondary batteries are manufactured in various forms, including prismatic, cylindrical, and pouch-type batteries.

[0006] A typical cylindrical secondary battery is configured by placing an electrolyte and electrode assembly in a metal housing, assembling a cap assembly on top, and sealing the upper part of the open housing through a crimping process using a crimping device.

[0007] In the crimping process of such conventional cylindrical batteries, there was a problem that the upper end or outer surface of the housing was scratched by the crimping device, or a burr or a pinching phenomenon occurred under the middle of the upper end of the housing, which often caused quality issues.

[0008] Therefore, there is a need to develop a crimping device for cylindrical batteries having a structure that can solve these problems.

[0009] The present invention was created in consideration of the above-described problems, and has as its primary purpose the provision of a crimping device that can facilitate the crimping process of a cylindrical battery and minimize the occurrence of scratches, dents, or burrs in the cylindrical battery during the crimping process.

[0010] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0011] According to one embodiment of the present invention for solving the above-described problem, a crimping device is provided, which is configured to crimp a housing of a cylindrical battery, and includes a punch configured to crimp the housing by pressing an upper end of the housing; and a fixing unit having a punch insertion portion configured to allow the punch to be inserted therein, and a can support portion configured to support at least a portion of the housing, form a step with the punch insertion portion, and extend in one direction from the punch insertion portion.

[0012] The can support may be configured to be at least partially spaced apart from the housing by a predetermined distance.

[0013] The can support may be configured such that the gap between the can support and the housing increases at least partially in the direction of the can support.

[0014] The above can support may include a tapered portion configured such that the inner width gradually increases in the above one direction.

[0015] The can support may include an insertion jaw configured to protrude at least partially inwardly and be inserted into a beading portion formed in the housing, and the tapered portion may be provided at a lower portion of the insertion jaw.

[0016] When the punch presses the upper portion of the housing, the upper surface of the can support and the punch may be configured to be spaced apart by a predetermined distance.

[0017] The above-mentioned fixed unit may include a plurality of fixed parts that are provided so as to be separable from each other, and a hollow space may be formed in which the plurality of fixed parts are configured to face each other and into which the cylindrical battery is inserted.

[0018] The corners of the portions where the above-mentioned plurality of fixed parts face each other can be formed into a round shape.

[0019] The corners of the above can support may have at least a partially rounded portion.

[0020] The radius of curvature of the above round portion can be configured to be approximately 0.2 mm or more.

[0021] According to one aspect of the present invention, by reducing the contact area between the crimping device and the outer surface of the housing of the cylindrical battery, scratches on the cylindrical battery can be minimized during the crimping process of the cylindrical battery.

[0022] In addition, according to another aspect of the present invention, it is possible to minimize the occurrence of a burr or a pinching phenomenon in a cylindrical battery during a crimping process of the cylindrical battery.

[0023] In addition, according to another aspect of the present invention, the issue of poor outer diameter dimensions of a cylindrical battery can be minimized.

[0024] In addition, the present invention may have various other effects, which will be described in each embodiment configuration, or the description of effects that can be easily inferred by those skilled in the art will be omitted.

[0025] The following drawings attached to this specification illustrate preferred embodiments of the present invention, and together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present invention, and therefore, the present invention should not be interpreted as being limited to matters described in such drawings.

[0026] Figure 1 is a schematic perspective view of a cylindrical battery applied to a crimping device according to one embodiment of the present invention.

[0027] Figure 2 is an exploded perspective view of a crimping device according to one embodiment of the present invention.

[0028] FIG. 3 is a schematic perspective view of a portion of a fixing unit of a crimping device according to one embodiment of the present invention.

[0029] FIG. 4 and FIG. 5 are drawings for explaining a crimping process of a cylindrical battery using a crimping device according to one embodiment of the present invention.

[0030] Fig. 6 is an enlarged view of a portion of Fig. 5, and is a drawing for explaining the tapered portion of the can support.

[0031] Fig. 7 is an enlarged view of a portion of Fig. 5, and is a drawing for explaining that the upper surface of the punch and the can support are spaced apart.

[0032] FIG. 8 is a drawing showing a top view of a plurality of fixed parts of a crimping device according to one embodiment of the present invention.

[0033] FIG. 9 is a drawing for explaining that a round portion is formed in a can support portion of a crimping device according to one embodiment of the present invention.

[0034] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, it should be noted that the terms and words used in this specification and claims should not be construed as limited to their conventional or dictionary meanings. Based on the principle that the inventor can appropriately define the concepts of terms to best explain his or her invention, they should be interpreted in a way that aligns with the technical spirit of the present invention.

[0035] Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention. Therefore, it should be understood that there may be various equivalents and modified examples that can replace them at the time of filing this application.

[0036] Furthermore, the present invention includes various embodiments. For each embodiment, redundant descriptions of substantially identical or similar components will be omitted, and the differences will be described.

[0037] Meanwhile, in the present invention, terms indicating directions such as up, down, left, right, front, and back may be used, but it is obvious to those skilled in the art that these terms are only for convenience of explanation and may vary depending on the location of the target object or the location of the observer.

[0038]

[0039] FIG. 1 is a schematic perspective view of a cylindrical battery applied to a crimping device according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of a crimping device according to one embodiment of the present invention, and FIG. 3 is a schematic perspective view of a portion of a fixing unit of a crimping device according to one embodiment of the present invention. In addition, FIGS. 4 and 5 are drawings for explaining a crimping process of a cylindrical battery using a crimping device according to one embodiment of the present invention.

[0040] A crimping device (1) according to one embodiment of the present invention may be a crimping device configured to crimp an opening formed on one side of a housing (120) of a cylindrical battery (100).

[0041] First, a cylindrical battery (100) applied to a crimping device (1) according to the present invention will be described with reference to FIGS. 1 and 4. In the present invention, the cylindrical battery (100) applied to the crimping device (1) may include an electrode assembly (110) and a housing (120). In addition, the cylindrical battery (100) may further include a current collector, a terminal, a top cap (130), etc. The cylindrical battery (100) may be a secondary battery configured to be capable of charging and discharging.

[0042] The electrode assembly (110) may include a first electrode having a first polarity, a second electrode having a second polarity, and a separator interposed between the first electrode and the second electrode. The electrode assembly (110) may have a jelly-roll structure.

[0043] Meanwhile, the present invention is not limited by the specific type or shape of the battery applied to the crimping device (1), and various batteries known at the time of filing of the present invention can be applied to the crimping device (1) of the present invention. In this embodiment, a crimping device (1) to which a cylindrical battery is applied as shown in the drawing is targeted, but it goes without saying that pouch-shaped or square-shaped batteries can be applied to the crimping device (1) of the present invention.

[0044] The housing (120) may have an opening formed on one side in the height direction (in the direction parallel to the Z-axis). The housing (120) may accommodate the electrode assembly (110) through the opening. The housing (120) may have a closed part formed on the other side in the height direction. That is, the housing (120) may have a form in which the upper end in the height direction is open and the lower end is closed.

[0045] The housing (120) may be made of a conductive metal material. The housing (120) may be electrically connected to the second electrode of the electrode assembly (110). Therefore, the housing (120) may have the same second polarity as the second electrode. The electrical connection between the electrode assembly (110) and the housing (120) may be made, for example, through a current collector.

[0046] Meanwhile, the top cap (130) may be configured to seal an opening formed on one side of the housing (120).

[0047] Referring mainly to FIGS. 2 to 5, a crimping device (1) according to one embodiment of the present invention is a device for sealing a cylindrical battery (100) by crimping an opening of a housing (120) in which an electrode assembly (110) and a top cap (130) are accommodated during the manufacturing process of the cylindrical battery (100).

[0048] A crimping device (1) may be equipped with a punch (10) and a fixing unit (20). The punch (10) may be configured to crimp the housing (120) by applying pressure to the upper portion of the housing (120) during the crimping process.

[0049] The fixing unit (20) is configured to fix the housing (120) so that it does not move during the crimping process, and may be configured to surround at least a portion of the housing (120). The fixing unit (20) may be configured to have a hollow space formed therein, and to at least partially surround the outer circumference of the housing (120) when the housing (120) is positioned in the hollow space.

[0050] More specifically, the fixing unit (20) may be provided with a punch insertion portion (21) and a can support portion (22). The punch insertion portion (21) may be configured to allow a punch to be inserted. The punch insertion portion (21) may be configured to guide the descent of the punch (10). The punch insertion portion (21) may be configured to allow the punch (10) to be inserted in a vertical direction.

[0051] The can support (22) may be configured to form a step with the punch insertion portion (21) and extend in one direction from the punch insertion portion (21). Here, the one direction may mean a direction toward the closed portion of the cylindrical battery (100). The can support (22) may be configured to support at least a portion of the housing (120). At this time, the inner diameter of the can support (22) may be configured to correspond to the outer diameter of the housing (120) in order to fix the cylindrical battery (100) so that it does not move.

[0052] That is, the fixed unit (20) can be configured so that there is a difference in the inner diameter of the lower and upper portions. The can support portion (22) can be said to be an area corresponding to the lower portion of the fixed unit (20), and the punch insertion portion (21) can be said to be an area corresponding to the upper portion of the fixed unit (20).

[0053] Meanwhile, the housing (120) may include a beading portion (122). The beading portion (122) may be formed on the upper portion of the electrode assembly (110). The beading portion (122) may be formed at an end of the battery housing (120) adjacent to the opening and may have a shape that is pressed inward. The beading portion (122) may facilitate fixing of the electrode assembly (110) and assembly of the top cap (130).

[0054] The can support (22) may further include an insertion protrusion (23) formed to protrude in the inner diameter direction. The insertion protrusion (23) may be configured such that at least a portion thereof protrudes inward and is inserted into a beading portion (122) formed in the housing (120). Accordingly, when the fixing unit (20) is mounted on the housing (120), the housing (120) can be fixed so as not to move in all of the up-down, left-right, and front-back directions by the can support (22).

[0055] At this time, the step forming the boundary between the can support (22) and the punch insertion portion (21) may be provided at a higher position than the insertion jaw (23). That is, the can support portion (22) may have its inner surface in contact with the outer surface of the housing (120) located at the upper side with respect to the beading portion (122), thereby supporting the housing (120) to the upper region of the beading portion (122).

[0056] Meanwhile, although the overall length of the fixed unit (20) in this embodiment is shown to be shorter than the length of the housing (120), the length of the fixed unit (20) can be designed to be longer or shorter, and a bracket or flange can be additionally provided on the outside of the fixed unit (20) for convenience of connection with a driving actuator (not shown).

[0057]

[0058] Referring to FIGS. 4 and 5, an example of a crimping process of a cylindrical battery (100) using a crimping device (1) according to the present embodiment will be described.

[0059] As illustrated in Fig. 4, a cylindrical battery (100) with a top cap (130) assembled therewith can be loaded into a crimping device (1) with the upper end of the housing (120) open. This cylindrical battery (100) can first be fixed by a fixing unit (20) so that the housing (120) does not move during the crimping process. At this time, the insertion protrusion (23) of the can support (22) is configured to fit into the beading portion (122) of the housing (120), so that the cylindrical battery (100) can be fixed more firmly.

[0060] Next, the punch (10) can be placed in the upper part of the fixed unit (20), i.e., in the punch insertion part (21). By pre-inserting the punch (10) in the punch insertion part (21) in the crimping preparation stage, the punch (10) can be safely guided in the punch insertion part (21) from the point where it starts to descend to pressurize the upper part of the housing (120). Accordingly, the pressing position error for the upper part of the housing (120) can be reduced compared to when there is no punch insertion part (21) or when the punch (10) is lowered outside the punch insertion part (21).

[0061] Next, the punch (10) can be lowered along the outer surface of the housing (120) toward the upper portion of the can support (22). At this time, the upper portion of the housing (120) in a vertical state is pressed by the punch (10) and deformed to a state tilted at a predetermined angle toward the central axis of the housing (120), thereby forming a crimping portion (121).

[0062] The crimping portion (121) may have an extended and banded shape to wrap around the edge of the top cap (130) positioned on the upper portion of the beading portion (122). By the shape of the crimping portion (121), the top cap (130) can be fixed on the beading portion (122).

[0063]

[0064] Fig. 6 is an enlarged view of a portion of Fig. 5, and is a drawing for explaining the tapered portion of the can support.

[0065] At this time, referring to FIG. 6, when the cylindrical battery (100) is fixed to the fixing unit (20) of the crimping device (1) in the crimping process of the cylindrical battery (100), the can support (22) may be configured to be at least partially spaced apart from the housing (120) by a predetermined distance.

[0066] According to the above-described embodiment of the present invention, the contact area between the crimping device (1) and the housing (120) of the cylindrical battery (100) is reduced, thereby minimizing the occurrence of scratches on the housing (120) during the crimping process of the cylindrical battery (100).

[0067] For example, as in the embodiment illustrated in FIG. 5, at least a portion of the housing (120) may be configured to be spaced apart from the can support (22) at the lower portion of the beading portion (122).

[0068] According to the above-described embodiment of the present invention, the housing (120) is tightly fixed to the can support (22) at the upper portion of the beading portion (122), so that fixing force for the cylindrical battery (100) can be secured during the crimping process.

[0069] More specifically, the can support (22) may be configured such that the distance between the can support (22) and the housing (120) increases at least partially as it goes in one direction. For example, as in the embodiment illustrated in FIG. 6, the can support (22) may be configured such that the distance between the can support (22) and the housing (120) increases at least partially as it goes downward. That is, the inner diameter of the can support (22) may be configured such that it gradually increases as it goes downward.

[0070] In other words, the can support (22) may include a tapered shape in one portion. The can support (22) may include a tapered portion (24) configured such that the inner width gradually increases in one direction.

[0071] According to the above-described embodiment of the present invention, the contact area between the crimping device (1) and the housing (120) of the cylindrical battery (100) is reduced, thereby minimizing the occurrence of scratches on the housing (120) during the crimping process of the cylindrical battery (100).

[0072] This tapered portion (24) may be provided at the lower portion of the insertion jaw (23). The tapered portion (24) may be configured to be spaced apart from the insertion jaw (23) by a predetermined distance. For example, the length (L) of the tapered portion (24) may be configured to be approximately 5 mm or more and 35 mm or less. Here, the length (L) of the tapered portion (24) may mean the vertical length of a portion in which the inner diameter of the can support portion (22) changes. In addition, the angle (θ) between the tapered portion (24) and the housing (120) may be configured to be approximately 5 degrees or more and 15 degrees or less.

[0073] If the length of the tapered portion (24) is too long or the gap between the tapered portion (24) and the insertion jaw (23) is too close, the area that the can support portion (22) secures to the lower part of the beading portion (122) of the housing (120) may become smaller, thereby weakening the securing force. According to the above-described embodiment of the present invention, the securing force between the housing (120) and the can support portion (22) can be secured while preventing scratches from occurring on the housing (120).

[0074]

[0075] Fig. 7 is an enlarged view of a portion of Fig. 5, and is a drawing for explaining that the upper surface of the punch and the can support are spaced apart.

[0076] The punch (10) may have a lower surface (11) configured to face the upper surface (22a) of the can support (22), and a pressing surface (12) configured to press the upper portion of the housing (120). The pressing surface (12) may include a curved section and a flat section that is approximately horizontal to the ground. Since the punch (10) has a curved pressing surface (12), the upper portion of the housing (120) may have a gentle round shape, thereby alleviating stress concentration in the corresponding portion.

[0077] Meanwhile, as in the embodiment illustrated in Fig. 7, when the punch (10) of the crimping device (1) presses the upper portion of the housing (120) during the crimping process of the cylindrical battery (100), the upper surface (22a) of the can support (22) and the punch (10) may be configured to be spaced apart from each other by a predetermined distance. That is, the lower surface (11) of the punch (10) and the can support (22) may be configured to be spaced apart from each other by a predetermined distance.

[0078] According to the above-described embodiment of the present invention, since the punch (10) descends at a predetermined distance from the upper surface (22a) of the can support (22), the contact area between the upper end of the housing (120) and the pressure surface (12) is very short. Therefore, the occurrence of scratches due to the upper end of the housing (120) being scratched by the crimping device (1) is minimized, and the phenomenon of the splitting (wear) of the upper end of the housing (120) can be improved.

[0079] At this time, the distance (d) between the can support (22) and the punch (10) can be minimized. For example, the distance (d) between the can support (22) and the punch (10) can be configured to be approximately 0.3 mm or less. As an example, during the crimping process of the cylindrical battery (100), the punch (10) can descend from the upper portion of the fixing unit (20) and enter the interior of the fixing unit (20), and can descend to the lower surface of the punch insertion portion (21). In other words, the lower surface (11) of the punch (10) can be blocked by the upper surface (22a) of the can support (22), thereby restricting the descent. According to the above-described embodiment of the present invention, by controlling the descending distance of the punch (10) to be constant, the deformation of the crimping portion (121) of the housing (120) can be made uniform.

[0080] According to the above-described embodiment of the present invention, the distance (d) between the can support (22) and the punch (10) is minimized, so that when the upper part of the housing (120) is greatly deformed due to the pressure of the punch (10), the corresponding part can be prevented from being pushed outward or a burr from being generated through the distance between the upper surface (22a) of the can support (22) and the punch (10).

[0081]

[0082] FIG. 8 is a drawing showing a view from above of a plurality of fixed parts of a crimping device according to one embodiment of the present invention, and FIG. 9 is a drawing for explaining that a round part is formed in a fixed part of a crimping device according to one embodiment of the present invention.

[0083] Meanwhile, a fixed unit (20) according to one embodiment of the present invention may include a plurality of fixed parts (20A, 20B, 20C, 20D) that are provided so as to be detachable from each other. For example, as in the embodiments illustrated in FIGS. 2 and 8, the fixed unit (20) may be formed of four fixed parts (20A, 20B, 20C, 20D) that are provided so as to be detachable from each other at a 90-degree angle.

[0084] A plurality of fixed parts (20A, 20B, 20C, 20D) may be arranged to form a hollow structure when connected to each other. That is, a plurality of fixed parts (20A, 20B, 20C, 20D) may face each other to form a hollow (O) into which a cylindrical battery (100) is inserted. These fixed parts (20A, 20B, 20C, 20D) may be configured to have horizontal access to the upright-arranged housing (120) and to fix the housing (120) along the circumferential direction of the housing (120).

[0085] At this time, the corners of the portions where the plurality of fixed parts (20A, 20B, 20C, 20D) face each other may be formed in a round shape. Specifically, referring to FIG. 9, at least some of the plurality of fixed parts (20A, 20B, 20C, 20D) may each have a round portion (25). The round portion (25) may be formed at least partially at the corner of the can support portion (22). The round portion (25) may be configured such that the corner of the can support portion (22) is R-processed (rounded) to have a predetermined radius of curvature. At this time, the radius of curvature of the round portion (25) may be configured to be approximately 0.2 mm or more.

[0086] According to the above-described embodiment of the present invention, the contact area between the crimping device (1) and the outer surface of the housing (120) of the cylindrical battery (100) is reduced, thereby minimizing the occurrence of scratches on the cylindrical battery (100) during the crimping process of the cylindrical battery (100). In addition, according to the above-described embodiment of the present invention, the occurrence of burrs or scratches on the cylindrical battery (100) during the crimping process of the cylindrical battery (100) is minimized, thereby reducing the outer diameter of the housing (120).

[0087]

[0088] As described above, the present invention has been described with reference to the attached drawings, focusing on preferred embodiments. However, it will be apparent to those skilled in the art that numerous obvious modifications can be made without departing from the scope of the present invention. Accordingly, the scope of the present invention should be construed as encompassing such numerous modifications by the appended claims.

Claims

1. A crimping device configured to crimp a housing of a cylindrical battery, A punch configured to crimp the housing by pressurizing the upper portion of the housing; and A crimping device characterized by comprising a fixing unit having a punch insertion portion configured to insert the punch, and a can support portion configured to support at least a portion of the housing, form a step with the punch insertion portion, and extend in one direction from the punch insertion portion.

2. In paragraph 1, A crimping device, characterized in that the can support is configured to be at least partially spaced apart from the housing by a predetermined distance.

3. In paragraph 2, A crimping device characterized in that the can support is configured such that the gap between the can support and the housing increases at least partially in the one direction.

4. In paragraph 1, A crimping device characterized in that the can support part includes a tapered part configured so that the inner width gradually increases in the one direction.

5. In paragraph 4, The above can support At least a portion of the insertion jaw is configured to protrude inwardly and be inserted into a beading portion formed in the housing, A crimping device characterized in that the tapered portion is provided at the lower portion of the insertion jaw.

6. In paragraph 1, A crimping device characterized in that when the punch presses the upper portion of the housing, the upper surface of the can support and the punch are configured to be spaced apart by a predetermined distance.

7. In paragraph 1, The above fixed unit includes a plurality of fixed parts that are arranged to be separated from each other, A crimping device characterized in that a hollow space is formed so that the plurality of fixed parts face each other and the cylindrical battery is inserted therein.

8. In paragraph 7, A crimping device characterized in that the edges of the portions where the plurality of fixed parts face each other are formed in a round shape.

9. In paragraph 7, A crimping device, characterized in that the corners of the can support portion have at least a partially rounded portion.

10. In paragraph 9, A crimping device, characterized in that the radius of curvature of the above round portion is configured to be approximately 0.2 mm or more.

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