Press fitting jig and maunfacturing method of secondary battery using same

Abstract

The present invention relates to a press-fit jig and a method for manufacturing a secondary battery using the same, wherein a protrusion protruding from the jig body presses the circumference of the top cap of the secondary battery to press the top cap into the lower can, thereby preventing the formation of indentation marks or lifting of corners caused by excessive pressure applied to the top cap and improving the quality and safety of the secondary battery. A press-fit jig according to the present invention is a press-fit jig for pressing a top cap so that the top cap is coupled to an opening of a lower can for a secondary battery, and comprises a hollow jig body portion and a protrusion portion that protrudes outwardly from the outer circumference of the jig body portion and has a pressing surface formed at the bottom portion that presses the top cap.

Description

Technology Field

[0001] The present invention relates to a press-fit jig and a method for manufacturing a secondary battery using the same, wherein a protrusion protruding from the jig body presses the circumference of the top cap of the secondary battery to press the top cap into the lower can, thereby preventing the formation of indentation marks or lifting of corners caused by excessive pressure applied to the top cap and improving the quality and safety of the secondary battery. Background Technology

[0002] Unlike primary batteries, which cannot be recharged, secondary batteries refer to batteries that can be charged and discharged. Types of secondary batteries include nickel-cadmium batteries, nickel-hydrogen batteries, lithium-ion batteries, and lithium-ion polymer batteries. These secondary batteries are used not only in small products such as digital cameras, laptops, mobile phones, PDAs, and E-bikes, but also in large products requiring high output such as electric vehicles and hybrid vehicles, as well as in power storage devices and backup power storage devices that store surplus generated power or renewable energy.

[0003] These secondary batteries are classified into pouch type and can type depending on the material of the battery case that accommodates the electrode assembly. The pouch type accommodates the electrode assembly in a pouch made of a flexible polymer material with an irregular shape. The can type accommodates the electrode assembly in a case made of a material such as metal or plastic with a uniform shape. Meanwhile, among can-type secondary batteries, small batteries in which the diameter is greater than the height are called button-type secondary batteries and are applied to electronic products such as various small wearable devices to supply power.

[0004] Looking at the structure of the button-type secondary battery, an electrode assembly is inserted into the internal space of the body of the lower can, and the opening of the lower can is covered by a top cap assembly (hereinafter referred to as 'top cap'). The top cap may include a base plate, a positive terminal provided on the upper part of the base plate, and an insulating member provided between the base plate and the positive terminal.

[0005] As such, the top cap is provided in the form of an assembly and can be seated and joined to the opening of the lower can as described above; for example, it can be joined to the lower can by laser welding via a seam welding method around the perimeter of the top cap. However, in this process, the top cap must first be inserted into the opening of the lower can, and conventionally, a press-fit jig was used to press the top cap from above to insert it into the lower can.

[0006] FIG. 1 is a perspective view illustrating a conventional press-fit jig, and FIG. 2 is a side cross-sectional view illustrating the press-fit jig being used to press a secondary battery. Referring to FIG. 1, the press-fit jig is described in detail. The conventional press-fit jig (10) is formed in a cylindrical shape and can press a top cap (22) seated on the lower can (21) of a secondary battery (20) from the top, as shown in FIG. 2. At this time, the inner diameter and outer diameter of the press-fit jig (10) are formed to be smaller than the diameter of the top cap (22), thereby enabling the press-fit jig (10) to directly press the top cap (22). However, since this press-fitting process is performed by controlling the position of the press-fitting jig (10) using a servo motor, there are limitations in controlling the force applied to the top cap (22), and if the press-fitting jig applies excessive pressure to the top cap (22), jig indentation marks may appear on the top cap (22) or the corners of the top cap (22) may lift up. Therefore, when performing the press-fitting process using a conventional press-fitting jig (10), defects in the appearance of the product and quality issues resulting therefrom may occur, and this may also be a factor in reducing the performance and safety of the battery. The problem to be solved

[0007] The present invention has been devised to solve the above problems, and the objective of the present invention is to provide a press-fit jig and a method for manufacturing a secondary battery using the same, wherein a protrusion protruding from the jig body presses the circumference of the top cap of a secondary battery to press the top cap into the lower can, thereby preventing the formation of indentation marks or lifting of corners caused by excessive pressure applied to the top cap and improving the quality and safety of the secondary battery. means of solving the problem

[0008] A press-fit jig according to Example 1 of the present invention is a press-fit jig for pressing a top cap so that the top cap is coupled to the opening of a lower can for a secondary battery, and comprises a hollow jig body and a protrusion that protrudes outward from the outer circumference of the jig body and has a pressing surface formed at the bottom that presses the top cap.

[0009] The lower end of the protrusion may be provided to protrude further toward the top cap than the lower end of the jig body.

[0010] The protrusion may be provided so that the pressure surface overlaps the circumference of the top cap and the lower can together to apply pressure.

[0011] The protrusions may be provided in multiple numbers along the outer surface of the jig body.

[0012] At least three protrusions are provided along the outer surface of the jig body, and with respect to the center of the jig body, the diameter of a virtual circle connecting the innermost of each protrusion is formed to be smaller than the outer diameter of the top cap, and the diameter of a virtual circle connecting the outermost of each protrusion is formed to be larger than the inner diameter of the lower can.

[0013] The protrusions may be provided at equal intervals on the outer surface of the jig body.

[0014] Four protrusions may be provided along the outer surface of the jig body, each spaced at equal intervals of 90 degrees.

[0015] The pressure surface can be formed as a flat plane.

[0016] The jig body can be formed in a cylindrical shape with an open bottom and a closed top.

[0017] The outer diameter of the jig body can be formed to be smaller than the outer diameter of the top cap.

[0018] The jig body can be position-controlled using a servo motor.

[0019] A method for manufacturing a secondary battery according to Example 2 of the present invention comprises, in a method for manufacturing a secondary battery using a press-fit jig, a step of placing a top cap on the upper part of a lower can and a step of pressing the top cap with a protrusion of the press-fit jig to bond it to the lower can.

[0020] The pressurizing step can press the top cap while the pressurizing surface of the protrusion overlaps the circumference of the top cap and the lower can together. Effects of the invention

[0021] The press-fit jig according to the present invention is a press-fit jig for pressing a top cap so that the top cap is coupled to the opening of a lower can for a secondary battery, and comprises a hollow jig body and a protrusion that protrudes outward from the outer circumference of the jig body and has a pressing surface formed at the bottom that presses the top cap. By pressing the top cap into the lower can by the protrusion pressing the circumference of the top cap, the press-fit jig can prevent the formation of indentation marks or lifting of corners caused by excessive pressure being applied to the top cap, thereby improving the quality and safety of the secondary battery. Brief explanation of the drawing

[0022] FIG. 1 is a perspective view illustrating a conventional press-fit jig. Figure 2 is a cross-sectional view illustrating a press-fit jig applying pressure to a secondary battery. FIG. 3 is a perspective view illustrating a press-fit jig according to Example 1 of the present invention. FIG. 4 is a side view illustrating a press-fit jig according to Example 1 of the present invention. Figure 5 is a cross-sectional view showing Figure 3 cut along the A-A' direction. FIG. 6 is a cross-sectional view showing the appearance of a secondary battery before pressurizing it using a press-fit jig according to Example 1 of the present invention. FIG. 7 is a cross-sectional view illustrating a secondary battery being pressed using a press-fit jig according to Example 1 of the present invention. Figure 8 is a plan view illustrating Figure 7 as seen from above. Specific details for implementing the invention

[0023] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0024] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.

[0025] Furthermore, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0027] Example 1

[0028] FIG. 3 is a perspective view illustrating a press-fit jig according to Embodiment 1 of the present invention. FIG. 4 is a side view illustrating a press-fit jig according to Embodiment 1 of the present invention. FIG. 5 is a cross-sectional view illustrating FIG. 3 cut along the A-A' direction. FIG. 6 is a cross-sectional view illustrating a secondary battery before pressurizing it using the press-fit jig according to Embodiment 1 of the present invention. FIG. 7 is a cross-sectional view illustrating a secondary battery after pressurizing it using the press-fit jig according to Embodiment 1 of the present invention. FIG. 8 is a top view illustrating FIG. 7.

[0029] First, referring to FIGS. 3, 4, and 5, a press-fit jig (100) according to Embodiment 1 of the present invention is a press-fit jig (100) for pressing a top cap so that the top cap is coupled to the opening of a lower can for a secondary battery, and comprises a jig body part (110) and a protrusion part (120). The jig body part (110) is hollow, and the protrusion part (120) protrudes outward from the outer circumference of the jig body part (110), and a pressing surface (120a) formed at the bottom presses the top cap. Here, the secondary battery may include all can-type secondary batteries, and preferably, it may be a button-type secondary battery in which the diameter is greater than the height and the cross-section is circular.

[0030] Conventionally, as shown in FIGS. 1 and 2, the press jig (10) was formed in a cylindrical shape without a separate protrusion to press the top cap (22) of the secondary battery (20). In particular, the inner and outer diameters of the press jig (10) were formed to be smaller than the diameter of the top cap (22), thereby allowing the top cap (22) to be pressed into the lower can (21). However, if the press jig (10) presses the top cap (22) excessively, an irregular arc-shaped indentation corresponding to a circle or part of a circle corresponding to the lower shape of the press jig (10) may occur on the top cap (22), or the corner of the top cap (22) that is not pressed on the outer circumference of the press jig (10) may lift up due to the pressing force of the press jig (10), resulting in an appearance defect. Such external defects not only lead to a decrease in the marketability and performance of the battery, but can also threaten the safety of the devices in which the battery is used and the users of those devices.

[0031] However, the press-fit jig (100) according to Embodiment 1 of the present invention illustrated in FIG. 3 has a protrusion (120) formed so as to protrude outward from the outer surface of the jig body (110), and in particular, the pressing surface (120a) formed at the bottom of the protrusion (120) presses the top cap, thereby applying appropriate pressure for insertion, which prevents irregularly shaped indentation marks from being formed on the top cap of the secondary battery and resolves the problem of defects in the appearance of the secondary battery.

[0032] In addition, as described below, the pressure surface (120a) of the protrusion (120) of the present invention can overlap the circumference of the top cap and the lower can together when applying pressure, and in this case, the lower can can act as a stopper during the process in which the pressure surface of the protrusion applies pressure to the top cap, thereby preventing excessive pressure from being applied to the top cap and preventing the formation of indentation marks and corner lifting.

[0033] Below, each component of the press-fit jig (100) will be described in detail with reference to FIGS. 3 to 8.

[0034] First, referring to FIG. 3, the jig body portion (110) is configured to form the body of the press-fit jig (100) and can be connected to an external pressurizing device to receive pressurizing force. It may have various shapes, but preferably, as shown in FIG. 3, FIG. 4 and FIG. 5, it can be formed in a cylindrical shape with an open bottom and a closed top. The jig body portion (110) can be connected to an external pressurizing device at the top and is formed to be open at the bottom, so that the top cap (220) can be pressed without damaging the top cap (220) even if the protruding area of ​​the top cap (220) is somewhat retracted during the pressurizing process.

[0035] Additionally, as shown in FIGS. 6 and 7, the outer diameter of the jig body portion (110) may be formed to be smaller than the outer diameter of the top cap (220) of the secondary battery (200). The jig body portion (110) may be formed in a cylindrical shape having thickness, where the outer diameter of the jig body portion (110) may refer to the diameter including the thickness of the jig body portion (110) when the cylindrical jig body portion (110) is cut in a horizontal direction. Furthermore, the fact that the outer diameter of the jig body portion (110) is formed to be smaller than the outer diameter of the top cap (220) may mean that when the jig body portion (110) is positioned so that its center corresponds to the top cap (220), the jig body portion (110) does not extend beyond the circumference of the top cap (220). In this way, the outer diameter of the jig body part (110) is formed to be smaller than the outer diameter of the top cap (220), so that the protrusion (120) protruding outward from the outer surface of the jig body part (110) can press against the top cap (220).

[0036] Meanwhile, the jig body (110) can be position-controlled using a servo motor. However, when using a servo motor, although precise position control is possible, there is a problem in that it is difficult to precisely adjust the pressure applied to the top cap (220), and this can be solved by the protrusion (120) described later.

[0037] Below, the configuration of the protrusion (120) will be described in detail with reference to FIGS. 6 to 8.

[0038] Referring to FIG. 6, the lower end of the protrusion (120) may be provided to protrude further toward the top cap (220) than the lower end of the jig body (110). Thus, the jig body (110) does not press the top cap (220), and the protrusion (120) can perform the function of pressing the top cap (220).

[0039] Additionally, as illustrated in FIGS. 7 and 8, the protrusion (120) can pressurize the perimeter of the top cap (220) and the lower can (210) together by overlapping the pressurizing surface (120a). Here, the pressurizing surface (120a) overlapping the perimeter of the top cap (220) and the lower can (210) together means that when the pressurizing jig (100) is positioned at the top of the top cap (220) such that its center corresponds to the top cap (220), a portion of the pressurizing surface (120a) is located on the upper part of the perimeter of the top cap (220), and the remaining portion of the pressurizing surface (120a) is located on the upper part of the lower can (210). However, the remaining portion of the pressurizing surface (120a) does not necessarily have to be entirely located on the upper part of the lower can (210), and may be located outside the lower can (210).

[0040] In this way, when the pressure surface (120a) of the protrusion (120) overlaps the circumference of the top cap (220) and the lower can (210), the pressure surface (120a) presses only the top cap (220) when the initial press jig (100) starts pressurizing the top cap (220), but after the top cap (220) is pressed into the lower can (210), the pressure surface (120a) comes into contact with the lower can (210), so that the lower can (210) can perform the role of a stopper, and the pressure transmitted to the top cap (220) by the lower can (210) is reduced, and consequently, excessive pressure is not applied to the top cap (220), thereby preventing the formation of indentation marks and corner lifting.

[0041] Additionally, the pressure surface (120a) can be formed as a flat surface, thereby uniformly pressing the top cap (220) and allowing the lower can (210) to act as a stopper when in contact with the lower can (210).

[0042] Meanwhile, the protrusions (120) may be provided in multiple numbers along the outer surface of the jig body (110). When multiple protrusions (120) are provided in this manner, the circular top cap (220) can be uniformly pressed to press the top cap (220) in a horizontal state, and if necessary, when the press jig (100) rotates, the position of the protrusions (120) can be slightly changed to press between the multiple protrusions (120) and the protrusions (120).

[0043] To explain in more detail the number and location of the protrusions (120), at least three protrusions (120) are provided along the outer surface of the jig body (110) as shown in FIG. 3, and the diameter (D1) of a virtual circle connecting the innermost part of each protrusion (120) with respect to the center of the jig body (110) is formed to be smaller than the outer diameter of the top cap (220), and the diameter (D2) of a virtual circle connecting the outermost part of each protrusion (120) is formed to be larger than the inner diameter of the lower can (210). Here, the diameter (D1) of the virtual circle connecting the innermost part of the protrusion (120) is formed to be smaller than the outer diameter of the top cap (220) so that when the center of the jig body part (110) is positioned to correspond to the center of the top cap (220) as shown in FIGS. 6 and 7, the protrusion (120) can press the top cap (220); and the diameter (D2) of the virtual circle connecting the outermost part of the protrusion (120) is formed to be larger than the inner diameter of the lower can (210) so that the protrusion (120) presses the top cap (220) and is positioned to overlap with a part of the lower can (210), so that after the top cap (220) is pressed into the opening of the lower can (210), no additional pressing force is transmitted and the lower can (210) can act as a stopper.

[0044] Additionally, as shown in FIG. 8, the protrusions (120) may be provided at equal intervals on the outer surface of the jig body (110), thereby uniformly pressing the top cap (220) so that the top cap (220) can be pressed horizontally. In detail, four protrusions (120) are provided along the outer surface of the jig body (110), each spaced at equal intervals of 90 degrees, so as to stably press the top cap (220).

[0046] Example 2

[0047] Example 2 of the present invention differs from Example 1 in that it is a method for manufacturing a secondary battery using the press-fit jig of Example 1. Content common to Example 1 will be omitted as much as possible, and Example 2 will be described focusing on the differences. That is, it is obvious that if content not explained in Example 2 is required, it can be considered as the content illustrated in Example 1 and FIGS. 3 to 8.

[0048] A method for manufacturing a secondary battery according to Embodiment 2 of the present invention comprises, in a method for manufacturing a secondary battery (200) using a press-fit jig (100), a step of placing a top cap (220) on the upper part of a lower can (210) and a step of pressing the top cap (220) with a protrusion (120) of the press-fit jig (100) to combine it with the lower can (210). Here, the press-fit jig (100) is a press-fit jig (100) that presses the top cap (220) so that the top cap (220) is combined with the opening of the lower can (210) for the secondary battery (200), and includes a hollow jig body part (110) and a protrusion (120) that protrudes outward from the outer surface of the jig body part (110) and has a pressing surface (120a) formed at the bottom that presses the top cap (220). Other detailed configurations and effects of the press-fit jig (100) can be understood in the same way as described in Example 1 above.

[0049] Thus, the method for manufacturing a secondary battery (200) according to Embodiment 2 of the present invention can apply appropriate pressure by pressing the top cap (220) with the protrusion (120) of the press jig (100) when performing the press-fitting process of the top cap (220) in the press-fitting step, thereby preventing the formation of circular indentation marks on the top cap (220) of the secondary battery (200) and resolving the problem of defects in the appearance of the secondary battery (200).

[0050] Meanwhile, the pressurizing step can press the top cap (220) while the pressurizing surface (120a) of the protrusion (120) overlaps the circumference of the top cap (220) and the lower can (210). In this way, when the top cap (220) is pressed while the pressure surface (120a) of the protrusion (120) overlaps the circumference of the top cap (220) and the lower can (210), the top cap (220) is pressed into the lower can (210), and the lower can (210) can act as a stopper from the point where the height of the circumference of the top cap (220) and the lower can (210) are equal, thereby preventing excessive pressure from being applied to the top cap (220) and preventing the formation of indentation marks on the top cap (220) or the lifting of the corners of the top cap (220), thereby minimizing defects in the appearance of the secondary battery (200).

[0051] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0052] 100: Press-fit jig 110: Jig body 120: Protrusion 120a: Pressurized surface 200: Secondary battery 210: Bottom can 220: Top Cap

Claims

Claim 1 A press-fit jig for pressing a top cap so that the top cap is coupled to the opening of a lower can for a secondary battery, comprising: a hollow jig body; and a protrusion that protrudes outward from the outer circumference of the jig body and has a pressing surface formed at the bottom that presses the top cap, wherein the protrusion is provided in a plurality along the outer circumference of the jig body and the pressing surface is provided to press the top cap by overlapping the circumference of the top cap and the lower can together. Claim 2 A press-fit jig according to claim 1, wherein the lower end of the protrusion is provided to protrude further toward the top cap than the lower end of the jig body. Claim 3 delete Claim 4 delete Claim 5 A press-fit jig according to claim 1, wherein the protrusions are provided in at least three or more along the outer surface of the jig body, and with respect to the center of the jig body, the diameter of a virtual circle connecting the innermost of each protrusion is formed to be smaller than the outer diameter of the top cap, and the diameter of a virtual circle connecting the outermost of each protrusion is formed to be larger than the inner diameter of the lower can. Claim 6 In claim 1, the protrusions are press-fit jigs provided at equal intervals on the outer surface of the jig body part. Claim 7 In claim 6, the above protrusions are provided in four places along the outer surface of the jig body part, each spaced at equal intervals of 90 degrees, forming a press-fit jig. Claim 8 In claim 1, the above-mentioned pressure surface is a press-fit jig formed as a flat plane. Claim 9 In claim 1, the jig body portion is a press-fit jig formed in a cylindrical shape with an open bottom and a closed top. Claim 10 A press-fit jig according to claim 1, wherein the outer diameter of the jig body portion is formed to be smaller than the outer diameter of the top cap. Claim 11 In claim 1, the jig body is a press-fit jig whose position is controlled using a servo motor. Claim 12 A method for manufacturing a secondary battery using a press-fit jig of claim 1, comprising: a step of seating a top cap on the upper part of a lower can; and a pressing step of pressing the top cap with a protrusion of the press-fit jig to bond it to the lower can. Claim 13 In claim 12, the above-mentioned pressurizing step is a method for manufacturing a secondary battery in which the pressurizing surface of the above-mentioned protrusion presses the top cap while overlapping the circumference of the top cap and the lower can together.

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