Secondary battery inspection device

Abstract

The secondary battery inspection device according to an embodiment of the present invention for solving the problem comprises: a plurality of first mirrors radially arranged and spaced apart from the central axis of a body by a first radius; a plurality of second mirrors radially arranged and spaced apart from the central axis by a second radius smaller than the first radius; a plurality of prism mirrors radially arranged inside the plurality of first mirrors and the plurality of second mirrors, to face the plurality of first mirrors and the plurality of second mirrors, and spaced apart from the central axis by a third radius smaller than the second radius; and a light receiving part for receiving light reflected through the prism mirrors.

Description

Secondary battery inspection device

[0001] Cross-citation with related applications

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2024-0195018 filed on December 24, 2024, and all contents disclosed in the document of said Korean Patent Application are incorporated herein as part of this specification.

[0003] Technology field

[0004] The present invention relates to a secondary battery inspection device, and more specifically, to a secondary battery inspection device that can reduce inspection costs and time and increase the utilization of facility space by performing inspections of the exterior and interior of a secondary battery can in a single procedure.

[0005] Generally, there are various types of secondary batteries, such as nickel-cadmium batteries, nickel-hydrogen batteries, lithium-ion batteries, lithium-ion polymer batteries, and lithium-metal batteries. These secondary batteries are used in many places, including small products such as smartphones, laptops, tablet PCs, smartwatches, smart glasses, portable gaming devices, and electric bicycles, as well as large products requiring high output such as electric vehicles and hybrid vehicles, and energy storage systems (ESS) and backup power storage devices that store surplus power or renewable energy.

[0006] A secondary battery comprises an electrode assembly formed by alternately stacking electrodes and separators, and a battery case that houses the electrode assembly. Depending on the type of battery case housing the electrode assembly, such secondary batteries are classified into pouch type and can type. The pouch type houses the electrode assembly in a pouch-type battery case made of a flexible material. The can type houses the electrode assembly in a can-type battery case made of a rigid material such as metal, and is classified into cylindrical type and prismatic type according to its shape.

[0007] In the case of conventional cylindrical secondary batteries, a separate electrode tab or lead exists to connect the current collector plate and the cap assembly, so there was no need to perform welding between the current collector plate and the battery can. However, in the case of the recently introduced tabless secondary battery, there is no electrode tab or lead, so welding must be performed between the current collector plate and the battery can to electrically connect the current collector plate to the battery can.

[0008] When welding is performed, a weld bead is formed in the weld area between the current collector plate and the battery can, leaving a trace of the weld; therefore, an inspection of the interior of the cylindrical battery can must be performed. Additionally, since welding forms a backbead on the opposite side of the weld area, an inspection of the exterior of the cylindrical battery can must also be performed.

[0009] As such, in cylindrical battery cans, the weld bead and back bead are formed on the inside and outside of the battery can, respectively, in the same welding area where welding was performed. However, conventionally, inspections of the outside and inside of the cylindrical battery can were performed separately, which was cumbersome as it required performing the inspection procedure twice and also took a long time. In addition, since two types of inspection modules, such as an external inspection module and an internal inspection module for the cylindrical battery can, had to be prepared separately, the costs for installation and maintenance were high, and there was also a problem of the space inside the facility becoming cramped.

[0010] The problem that the present invention aims to solve is to provide a secondary battery inspection device that can reduce inspection costs and time and increase the utilization of facility space by performing inspections of the exterior and interior of a secondary battery can in a single procedure.

[0011] The problems of the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0012] A secondary battery inspection device according to an embodiment of the present invention for solving the above problem comprises: a plurality of first mirrors formed radially and spaced apart from the central axis of a body by a first radius; a plurality of second mirrors formed radially and spaced apart from the central axis by a second radius smaller than the first radius; a plurality of prism mirrors formed radially and spaced apart from the central axis by a third radius smaller than the second radius, arranged in a direction facing each of the plurality of first mirrors and the plurality of second mirrors, respectively; and a light receiving unit that receives light reflected through the prism mirrors.

[0013] Alternatively, the plurality of first mirrors may be arranged at equal angles around the central axis, and the plurality of second mirrors may be arranged at equal angles around the central axis.

[0014] Alternatively, the plurality of first mirrors and the plurality of second mirrors may be arranged alternately one by one.

[0015] Alternatively, the plurality of first mirrors and the plurality of second mirrors may be arranged at equal angles to each other around the central axis.

[0016] Alternatively, the plurality of prism mirrors may be arranged at equal angles around the central axis.

[0017] Alternatively, the plurality of prism mirrors may be formed in a number equal to the sum of the number of the plurality of first mirrors and the plurality of second mirrors.

[0018] Alternatively, the plurality of prism mirrors may each be arranged in a direction facing one of the plurality of first mirrors and the plurality of second mirrors.

[0019] Alternatively, it may further include a camera positioned toward the light receiving unit to capture light incident on the light receiving unit.

[0020] Alternatively, the plurality of first mirrors may be formed with an inclination at a first angle of inclination from the central axis, and the plurality of second mirrors may be formed with an inclination at a second angle of inclination smaller than the first angle of inclination from the central axis.

[0021] Alternatively, it may further include an adjustment unit for adjusting the first radius, the first angle of inclination, the second radius, and the second angle of inclination.

[0022] Alternatively, the adjustment unit may include an upper adjustment bolt for moving the upper portion of the plurality of first mirrors or the plurality of second mirrors; and a lower adjustment bolt for moving the lower portion of the plurality of first mirrors or the plurality of second mirrors.

[0023] Alternatively, it may further include an actuator that rotates the plurality of first mirrors and the plurality of second mirrors around the central axis of the body.

[0024] Alternatively, the actuator may rotate the plurality of first mirrors and the plurality of second mirrors by an angle at which the first mirror and the second mirror adjacent to each other are separated.

[0025] Alternatively, it may further include a pusher that supports the secondary battery to be inspected from below and rotates around the central axis of the body.

[0026] Alternatively, the pusher may rotate by an angle at which the first mirror and the second mirror, which are adjacent to each other, are separated.

[0027] Alternatively, the plurality of first mirrors and the plurality of second mirrors may have a viewing angle greater than the angle separated from the first mirror or the second mirror adjacent to each other.

[0028] Other specific details of the present invention are included in the detailed description and drawings.

[0029] According to embodiments of the present invention, at least the following effects are achieved.

[0030] Since inspection of the exterior and interior of a secondary battery can can be performed in a single procedure using only a single secondary battery inspection device, inspection time and costs can be reduced and the utilization of facility space can be increased.

[0031] The effects according to the present invention are not limited to those exemplified above, and various other effects are included in this specification.

[0032] Figure 1 is a cross-sectional view of a cylindrical secondary battery (1).

[0033] FIG. 2 is an enlarged cross-sectional view showing a beading portion (114) formed on a cylindrical battery can (11).

[0034] FIG. 3 is an enlarged cross-sectional view showing the sealing gasket (18) and can cover (17) inserted through the opening (113) of the cylindrical battery can (11).

[0035] FIG. 4 is an enlarged cross-sectional view showing the appearance of a cylindrical secondary battery (1) with a crimping process performed to form a crimped portion (115).

[0036] FIG. 5 is an enlarged cross-sectional view showing the beading portion (114) of a cylindrical secondary battery (1) and the second current collector plate (132) being welded together.

[0037] FIG. 6 is a planar perspective view of a secondary battery inspection device (2) according to one embodiment of the present invention.

[0038] FIG. 7 is a bottom perspective view of a secondary battery inspection device (2) according to one embodiment of the present invention.

[0039] FIG. 8 is a bottom view of a secondary battery inspection device (2) according to one embodiment of the present invention.

[0040] Figure 9 is a cross-sectional view taken along A-A' in Figure 8.

[0041] Figure 10 is a cross-sectional view taken along B-B' in Figure 8.

[0042] FIG. 11 is a schematic diagram of a secondary battery inspection device (2) according to another embodiment of the present invention.

[0043] The advantages and features of the present invention and the methods for achieving them will become clear by referring to the embodiments described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below but may be implemented in various different forms. These embodiments are provided merely to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Throughout the specification, the same reference numerals refer to the same components.

[0044] Unless otherwise defined, all terms used in this specification (including technical and scientific terms) may be used in a meaning that is commonly understood by those skilled in the art to which the present invention pertains. Additionally, terms defined in commonly used dictionaries are not to be interpreted ideally or excessively unless explicitly and specifically defined otherwise.

[0045] The terms used herein are for describing the embodiments and are not intended to limit the invention. In this specification, the singular form includes the plural form unless specifically stated otherwise in the text. As used herein, "comprises" and / or "comprising" do not exclude the presence or addition of one or more other components in addition to the components mentioned.

[0046] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0047] Figure 1 is a cross-sectional view of a cylindrical secondary battery (1).

[0048] The cylindrical secondary battery (1) may be a large cylindrical secondary battery with a form factor ratio of 0.4 or more. Here, the form factor refers to a value representing the diameter and height of the cylindrical secondary battery, and the form factor ratio refers to the ratio of the diameter (Φ) to the height (H) of the cylindrical secondary battery.

[0049] In the figures representing the form factor, the first two numbers represent the diameter of the cylindrical secondary battery (1), and the next two or three numbers represent the height of the cylindrical secondary battery (1). The cylindrical secondary battery (1) may, for example, have a form factor of 46110 (diameter 46 mm, height 110 mm, form factor ratio 0.418), 4875 (diameter 48 mm, height 75 mm, form factor ratio 0.640), 48110 (diameter 48 mm, height 110 mm, form factor ratio 0.436), 4880 (diameter 48 mm, height 80 mm, form factor ratio 0.600), and 4680 (diameter 46 mm, height 80 mm, form factor ratio 0.575). In particular, the 4680 secondary battery, which is a tabless secondary battery, is a secondary battery that is larger in size, has a higher energy density relative to volume, reduces costs, and improves durability and lifespan compared to the existing 18650 (diameter 18mm, height 65mm, form factor ratio 0.277) and 21700 (diameter 21mm, height 70mm, form factor ratio 0.3) secondary batteries, and demand for it has recently been increasing.

[0050] A cylindrical secondary battery (1) may include an electrode assembly (10), a cylindrical battery can (11), a first current collector plate (131), a second current collector plate (132), a rivet terminal (14), an insulating gasket (15), an insulator (16), a can cover (17), and a sealing gasket (18).

[0051] The electrode assembly (10) is a laminate formed by stacking electrodes and a separator. Specifically, the electrode assembly (10) is a laminated structure in which two types of electrodes, such as a positive electrode and a negative electrode having a wide plate shape, and a separator interposed between the electrodes and further disposed on one side of either electrode are stacked. This electrode assembly (10) may be a Jelly Roll electrode assembly (10) in which the positive electrode, negative electrode, and separator are each formed into a wide and long sheet shape, stacked, and then wound in one direction from one end to the other. However, the electrode assembly (10) is not limited thereto and may have various forms, such as a stack type or an L&S (Lamination & Stack) type in which a plurality of positive electrodes, negative electrodes, and separators of a predetermined size are repeatedly and alternately stacked, or a stack and folding type in which a plurality of positive electrodes and negative electrodes of a predetermined size are stacked with a long sheet-shaped separator in between and then the separator is folded. Hereinafter, the electrode assembly (10) is described as a jelly roll electrode assembly (10), but this is for convenience of explanation and not to limit the scope of rights.

[0052] Two types of electrodes, such as a positive electrode and a negative electrode, may each have a structure in which an active material layer is formed on an electrode current collector in the form of a metal foil or a metal mesh. The active material layer is typically formed by dispersing granular active material, conductive material, binder, and plasticizer in a solvent to form a slurry, stirring the mixture, applying the active material slurry to the electrode current collector, and then removing the solvent during a drying process. Additionally, there may be a non-active area (12) in which the active material layer is not formed in a portion of the electrode current collector.

[0053] Conventionally, a pair of tabs or leads corresponding to each electrode were attached to these non-positive parts. The positive tab attached to the positive non-positive part was electrically connected to the cap assembly, and the negative tab attached to the negative non-positive part was electrically connected to the bottom of the battery can. However, recently, a secondary battery (1) with a tabless structure has been introduced in which no separate tab or lead is attached to the non-positive part, and a part of the non-positive part substantially performs the role of an electrode tab.

[0054] As illustrated in FIG. 1, the secondary battery (1) may be a tabless secondary battery (1) that does not include electrode tabs. First, a long sheet-shaped positive electrode, a separator, and a negative electrode are sequentially stacked. At this time, the positive electrode and the negative electrode each include a blank portion where no active material is formed, and the first electrode blank portion (121) and the second electrode blank portion (122) may each be formed long in the longitudinal direction of the long sheet-shaped electrode. The first electrode blank portion (121) and the second electrode blank portion (122) may be arranged in opposite directions. When such a stack is wound in one direction from one end to the other, a jelly roll electrode assembly (10) included in the tabless secondary battery (1) is manufactured. The first electrode blank portion (121) and the second electrode blank portion (122) of the electrode assembly (10) are connected to the first current collection plate (131) and the second current collection plate (132), respectively. The current collection plate (13) has a larger cross-sectional area compared to the strip-type electrode tab, and since resistance is inversely proportional to the cross-sectional area of ​​the current-carrying path, if the secondary battery (1) is formed with such a structure, the internal resistance of the secondary battery (1) can be greatly reduced.

[0055] The first electrode blank portion (121) and the second electrode blank portion (122) can be formed into a plurality of segments that can be independently folded. To this end, a metal foil cutting process such as laser notching, ultrasonic cutting, or punching can be performed on the first electrode blank portion (121) and the second electrode blank portion (122) to form a plurality of segments. Then, at least some of these segments can be folded toward the winding center (C) of the electrode assembly (10).

[0056] The current collection plate (13) and the electrode base (12) are generally joined by welding. To improve welding characteristics, strong pressure must be applied to the welding area of ​​the electrode base (12) to bend the electrode base (12) as flat as possible. However, if the electrode base is not formed in the form of multiple segments, the shape of the base may be deformed during this bending process, and the deformed area may come into contact with the electrode of opposite polarity, causing an internal short circuit or inducing fine cracks in the base. However, if the first electrode base (121) and the second electrode base (122) are formed in the form of multiple segments that can be bent independently, the stress applied to the base during bending can be reduced, thereby minimizing deformation and damage to the base.

[0057] In addition, when the first electrode uncoordinated portion (121) and the second electrode uncoordinated portion (122) are formed in the form of segments, when bending, multiple segments overlap each other to form a bending surface, which increases the welding strength with the current collection plate (13) and prevents the problem of the laser penetrating into the electrode assembly (10) and abrading the separator or active material when performing welding such as laser welding, thereby improving the welding characteristics with the current collection plate (13). When multiple segments are bent and overlap each other to form a bending surface, a current collection plate (13) can be connected to this bending surface at each end of the electrode assembly (10).

[0058] When the first electrode blank portion (121) is formed in the shape of a plurality of segments, at least some of the plurality of segments are formed protruding downward from the electrode assembly (10) based on FIG. 1. Then, when these plurality of segments are bent and overlapped to form a first electrode bent surface, the first electrode bent surface can be connected to the first current collection plate (131) by welding or the like. When the second electrode blank portion (122) is formed in the shape of a plurality of segments, at least some of the plurality of segments are formed protruding upward from the electrode assembly (10) based on FIG. 1. Then, when these plurality of segments are bent and overlapped to form a second electrode bent surface, the second electrode bent surface can be connected to the second current collection plate (132).

[0059] Meanwhile, an insulating layer may be further formed on the electrode. Specifically, the insulating layer may be formed along the direction in which the electrode assembly (10) is wound, covering a portion of the electrode active material layer and a portion of the electrode uncoated portion (12). When the first electrode uncoated portion (121) and the second electrode uncoated portion (122) are folded, the first electrode uncoated portion (121) and the second electrode uncoated portion (122) are positioned close to the electrode of opposite polarity beyond the separator, and as a result, the positive and negative electrodes may come into electrical contact, potentially causing an internal short circuit. However, if the insulating layer covers a portion of the electrode active material layer and a portion of the uncoated portion, the insulating layer prevents the positive and negative electrodes from coming into electrical contact, thereby preventing a short circuit from occurring inside the secondary battery (1).

[0060] A cylindrical battery can (11) accommodates an electrode assembly (10) in its internal space. The battery can (11) is a case in which an electrode assembly (10) and an electrolyte can be accommodated inside through an opening (113) formed at one end, and is manufactured from an electrically conductive metal material such as aluminum or steel. Based on FIG. 1, an opening (113) is formed on the upper side of the battery can (11), and the opening (113) can be covered by a can cover (17) in a subsequent process. The lower part (111) and the side part (112) of the battery can (11) are connected to each other and, preferably, can be formed integrally with each other. The lower part (111) of the battery can (11) is formed to be approximately flat, and when the electrode assembly (10) and the electrolyte are accommodated inside the battery can (11), the lower part (111) of the battery can (11) supports the electrode assembly (10) from below. And the side (112) of the battery can (11) is formed in a cylindrical shape to support the electrode assembly (10) from the side, and it is preferable that its diameter be larger than the diameter of the electrode assembly (10) by the size of the offset. If the diameter of the side (112) of the battery can (11) is smaller than or equal to the diameter of the electrode assembly (10), the electrode assembly (10) is not inserted into the interior of the battery can (11). And if the diameter of the side (112) of the battery can (11) is excessively larger than the diameter of the electrode assembly (10), the electrode assembly (10) may shake significantly inside the battery can (11) or deviate from its proper position, and the space utilization of the secondary battery (1) may be reduced, and the energy density relative to volume may decrease.

[0061] The rivet terminal (14) is manufactured from an electrically conductive metal material and is formed by penetrating the lower part (111) of the battery can (11) with reference to FIG. 1, and protrudes downward from the battery can (11) so that a portion is exposed to the outside. To this end, the rivet terminal (14) can be fixed by riveting from the lower part (111) of the battery can (11). The rivet terminal (14) can be formed by penetrating approximately the center of the lower part (111) of the battery can (11). And, this rivet terminal (14) is connected to the first current collector plate (131) through welding, etc.

[0062] Specifically, the rivet terminal (14) includes an outer terminal portion (141) exposed to the outside of the battery can (11), an inner terminal portion (142) fixed to the battery can (11) from the inside of the battery can (11), and a terminal connecting portion (143) that connects the outer terminal portion (141) and the inner terminal portion (142) to each other and penetrates a terminal hole formed in the lower part (111) of the battery can (11).

[0063] The outer part of the terminal (141) is exposed to the outside of the battery can (11) and may have a disc shape, but is not limited thereto and may have various shapes such as a polygon. The inner part of the terminal (142) is located inside the battery can (11) and is connected to the first current collection plate (131). The terminal connection part (143) connects the outer part of the terminal (141) and the inner part of the terminal (142), and at this time, it is preferable to connect the approximate center of the outer part of the terminal (141) and the inner part of the terminal (142).

[0064] The terminal outer portion (141), terminal inner portion (142), and terminal connecting portion (143) can be formed integrally. Accordingly, the terminal outer portion (141), terminal connecting portion (143), and terminal inner portion (142) can be approached from the outside of the terminal hole, and the terminal inner portion (142) and terminal connecting portion (143) can be inserted into the terminal hole. When the terminal inner portion (142) is riveted, the terminal inner portion (142) is deformed inside the battery can (11) and may have a bent shape toward the bottom (111) of the battery can (11). In this way, the riveted terminal (14) can be fixed to the battery can (11) and the riveted terminal (14) can be formed in the terminal hole. At this time, in order for the rivet terminal (14) to be fixed to the lower part (111) of the battery can (11) without detaching from the terminal hole again, it is preferable that the diameter of the terminal hole be smaller than the diameters of the terminal outer part (141) and the terminal inner part (142). In particular, the diameter of the terminal inner part (142) is initially formed to be smaller than the diameter of the terminal hole, and when the terminal inner part (142) is inserted into the terminal hole and then riveted, the diameter of the terminal inner part (142) may become larger than the diameter of the terminal hole.

[0065] The first current collector plate (131) is made of an electrically conductive metal material and is connected to the first electrode non-positive portion (121) of the electrode assembly (10), and at the same time is also connected to the rivet terminal (14), particularly the inner portion (142) of the terminal. By doing so, it serves as a passage that electrically connects the first electrode non-positive portion (121) of the electrode assembly (10) and the rivet terminal (14). Thus, the rivet terminal (14) can serve as a terminal of the first polarity. If the first electrode is positive, the first current collector plate (131) and the rivet terminal (14) have positive polarity.

[0066] The second current collector plate (132) is made of a metal material having electrical conductivity and is connected to the second electrode non-conductive portion (122) of the electrode assembly (10), and at the same time is also connected to the battery can (11). By doing so, it serves as a passage that electrically connects the second electrode non-conductive portion (122) of the electrode assembly (10) and the battery can (11). Thus, the battery can (11) can serve as a negative terminal. If the second electrode is a negative electrode, the second current collector plate (132) and the battery can (11) have negative polarity.

[0067] Since the rivet terminal (14) and the battery can (11) have different polarities, the rivet terminal (14) and the battery can (11) must be electrically insulated from each other. Therefore, an insulating gasket (15) made of an insulating material may be interposed between the rivet terminal (14) and the battery can (11). However, this is not limited thereto, and various methods may be used to insulate the rivet terminal (14) and the battery can (11), such as applying an insulating adhesive or interposing an insulating film between the rivet terminal (14) and the battery can (11).

[0068] An insulating gasket (15) is interposed between a rivet terminal (14) and a lower part (111) of a battery can (11) to insulate each other. This insulating gasket (15) includes an outer gasket part (151) formed between the outer part of the terminal (141) and the outer surface of the lower part (111) of the battery can (11), an inner gasket part (152) formed between the inner part of the terminal (142) and the inner surface of the lower part (111) of the battery can (11), and a gasket connecting part (153) that connects the outer part of the gasket (151) and the inner part of the gasket (152) to each other and penetrates the terminal hole.

[0069] The outer part (151), inner part (152), and gasket connection part (153) of the insulating gasket (15) can all be formed integrally. In addition, a gasket hole is formed in the center of the insulating gasket (15), so that the outer part (151) and the inner part (152) of the gasket may have a disc ring shape, and the rivet terminal (14) passes through the gasket hole.

[0070] In order for the gasket connection part (153) to be fixed to the lower part (111) of the battery can (11) without detaching from the terminal hole after being inserted through the terminal hole, it is preferable that the diameter of the terminal hole be smaller than the diameter of the outer part (151) and the inner part (152) of the gasket. Also, in order for the rivet terminal (14) to be fixed to the lower part (111) of the battery can (11) without detaching from the gasket hole after being inserted through the gasket hole, it is preferable that the diameter of the gasket hole be smaller than the diameter of the outer part (141) and the inner part (142) of the terminal. When the insulating gasket (15) is inserted through the terminal hole, the gasket connection part (153) is placed in the terminal hole, and the gasket connection part (153) can be fixed to the lower part (111) of the battery can (11). And, when the rivet terminal (14) is inserted through the gasket hole, the terminal connection part (143) is placed in the gasket hole, and when the terminal inner part (142) is riveted inside the terminal hole, the terminal inner part (142) is bent toward the lower part (111) of the battery can (11) inside the battery can (11) and the rivet terminal (14) can be fixed to the battery can (11).

[0071] The insulating gasket (15) is manufactured from a material having insulating properties, and it is particularly preferable to manufacture it from a material such as rubber, silicone, or an insulating polymer having flexibility and elasticity. If the diameter of the inner part (152) of the gasket is formed to be larger than the diameter of the terminal hole from the beginning, even if the diameter of the terminal hole is smaller than the diameter of the outer part (151) of the gasket and the inner part (152) of the gasket, the shape of the outer part (151) of the gasket or the inner part (152) of the gasket can be modified to easily penetrate and insert the terminal hole. However, it is not limited thereto, and the diameter of the inner part (152) of the gasket may be formed to be smaller than the diameter of the terminal hole from the beginning. And when the inner part of the gasket (152) and the inner part of the terminal (142) are inserted into the terminal hole and the inner part of the terminal (142) of the rivet terminal (14) is riveted inside the terminal hole, the inner part of the gasket (152) is also bent together with the inner part of the battery can (11) towards the lower part (111) of the battery can (11), and the diameter of the inner part of the gasket (152) may become larger than the diameter of the terminal hole.

[0072] In this way, when the insulating gasket (15) is interposed between the rivet terminal (14) and the battery can (11), the insulating gasket (15) insulates the rivet terminal (14) and the battery can (11), and at the same time, it may seal the rivet terminal (14) and the battery can (11) by being in close contact with them.

[0073] The outer part of the gasket (151) may be formed flat and interposed only between the outer part of the terminal (141) and the lower part (111) of the battery can (11), but is not limited thereto. The outer surface of the outer part of the gasket (151) may surround the outer surface of the outer part of the terminal (141) of the rivet terminal (14), and furthermore, may cover a part of the outer surface of the outer part of the terminal (141). In this case, when a bus bar, etc. is connected to the rivet terminal (14) to assemble a battery module, etc. later, the rivet terminal (14) and the battery can (11) may be electrically connected to each other, thereby preventing a short circuit from occurring.

[0074] Since the first current collector plate (131) and the battery can (11) have different polarities, the first current collector plate (131) and the battery can (11) must also be insulated from each other. Therefore, an insulator (16) made of an insulating material can be formed between the first current collector plate (131) and the battery can (11). This insulator (16) can insulate not only the first current collector plate (131) but also the first electrode non-contained portion (121) and the battery can (11). To this end, the insulator (16) may have a cap shape with an outer region bent. The rivet terminal (14) must be connected to the first current collector plate (131) while penetrating the lower portion (111) of the battery can (11) and being exposed to the outside. Therefore, the rivet terminal (14) may be formed penetrating approximately the center of the insulator (16).

[0075] The rivet terminal (14) acts as a terminal of the first polarity through the first current collection plate (131). And the area of ​​the lower part (111) of the battery can (11), excluding the rivet terminal (14) and the insulating gasket (15), acts as a terminal of the second polarity through the second current collection plate (132). For example, if the first polarity is positive, the rivet terminal (14) acts as a positive terminal, and if the second polarity is negative, the area of ​​the lower part (111) of the battery can (11), excluding the rivet terminal (14) and the insulating gasket (15), acts as a negative terminal. Therefore, since the positive terminal and the negative terminal of the cylindrical secondary battery (1) are both formed facing the same direction, when assembling multiple secondary batteries (1) to manufacture a battery module, etc., the structure of the battery module, etc., for connecting to each terminal can be simplified.

[0076] FIG. 2 is an enlarged cross-sectional view showing a beading portion (114) formed on a cylindrical battery can (11).

[0077] When the first current collector plate (131), the electrode assembly (10), the second current collector plate (132), and the electrolyte are received into the interior of the battery can (11) through the opening (113) formed at the top of the battery can (11), a beading portion (114) is formed at a location adjacent to the opening (113). As shown in FIGS. 1 and 2, the beading portion (114) has a shape that is indented inwardly to a predetermined depth from the outer surface of the battery can (11). The can connection portion (1323) of the second current collector plate (132) is seated on the upper surface of the beading portion (114), and the beading portion (114) and the second current collector plate (132) are connected to each other by welding or the like. By forming such a beading portion (114), it is possible to prevent the electrode assembly (10) from escaping to the outside through the opening (113) of the battery can (11) or from shaking significantly inside the battery can (11).

[0078] Recently, a cylindrical secondary battery (1) has been introduced that includes a battery can (11) in which such a beading portion (114) is absent or the depth of the beading portion (114) is very shallow. In this case, the can connection portion (1323) of the second current collector plate (132) may be directly connected to the upper inner wall of the battery can (11) by welding or the like.

[0079] FIG. 3 is an enlarged cross-sectional view showing the sealing gasket (18) and can cover (17) inserted through the opening (113) of the cylindrical battery can (11).

[0080] As shown in FIG. 3, after forming the beading portion (114), a sealing gasket (18) and a can cover (17) are inserted through the opening (113) of the battery can (11). The can cover (17) may have a roughly disc shape, and the sealing gasket (18) may have a disc ring shape along the outer surface of the can cover (17). The can cover (17) may be manufactured from a material such as metal with high rigidity, and the sealing gasket (18) may be manufactured from a material such as rubber, silicone, or an insulating polymer having flexibility and elasticity to seal between the can cover (17) and the battery can (11).

[0081] The diameters of the sealing gasket (18) and the can cover (17) may correspond to the diameter of the opening (113) of the battery can (11). Here, corresponding means that the diameters of the sealing gasket (18) and the can cover (17) are smaller than the diameter of the opening (113) of the battery can (11) by the size of the offset. If the diameters of the sealing gasket (18) and the can cover (17) are larger than or equal to the diameter of the opening (113) of the battery can (11), the sealing gasket (18) and the can cover (17) cannot be inserted into the interior of the battery can (11) through the opening (113). And if the diameters of the sealing gasket (18) and the can cover (17) are excessively smaller than the diameter of the opening (113) of the battery can (11), the can cover (17) may not be able to sufficiently cover the opening (113) of the battery can (11). Since the diameters of the sealing gasket (18) and the can cover (17) correspond to the diameter of the opening (113) of the battery can (11), the sealing gasket (18) and the can cover (17) can be easily inserted into the interior of the battery can (11), and when the crimping portion (115) is subsequently formed, the can cover (17) can sufficiently cover the opening (113) of the battery can (11) and seal the interior of the battery can (11).

[0082] The can cover (17) may be manufactured from a material such as metal. However, since the periphery of the can cover (17) is sealed by a sealing gasket (18), the can cover (17) may not have polarity as current does not flow through it. However, it is not limited to this, and as long as the can cover (17) can seal the opening (113) of the battery can (11), the can cover (17) may be fixed by being directly welded to the battery can (11) or fixed through a separate part. In this case, the sealing gasket (18) may not be included, and the can cover (17) may have the same polarity as the battery can (11).

[0083] The can cover (17) may include a venting portion (171) capable of discharging gas to the outside when the internal pressure increases due to gas generated inside the battery can (11). The venting portion (171) may be formed in at least a part of the can cover (17) with a thickness that is relatively thinner than other parts of the can cover (17). Thus, when the internal pressure of the battery can (11) increases, the venting portion (171), which is relatively thinner, breaks, thereby discharging the gas inside the battery can (11) to the outside.

[0084] The surrounding area of ​​the sealing gasket (18) and the can cover (17) is seated on the upper surface of the second current collection plate (132) and the upper surface of the beading surface. At this time, in order for the surrounding area of ​​the sealing gasket (18) and the can cover (17) to be stably seated on the upper surface of the second current collection plate (132) and the upper surface of the beading surface, the upper surface of the beading surface and the can connection portion (1323) of the second current collection plate (132) can be formed approximately flat.

[0085] FIG. 4 is an enlarged cross-sectional view showing the appearance of a cylindrical secondary battery (1) with a crimping process performed to form a crimped portion (115).

[0086] When the sealing gasket (18) and the can cover (17) are inserted through the opening (113) of the battery can (11), the upper portion of the battery can (11) forming the opening (113) of the battery can (11) is bent inward to form a crimping portion (115). As shown in FIGS. 1 and 4, the crimping portion (115) is formed by extending upward from the beading portion (114) and being bent in a direction toward the center of the battery can (11), thereby securing the sealing gasket (18) and the can cover (17). It also has a shape that covers the surrounding area of ​​the sealing gasket (18) and the can cover (17).

[0087] After forming the crimping portion (115), a sizing process is performed on the cylindrical battery can (11) so that the secondary battery (1) can be compressed in the height direction of the battery can (11). The sizing process is a process of applying pressure to the battery can (11) in the height direction to adjust the height of the secondary battery (1) to the designed form factor. When this sizing process is performed, the height of the battery can (11) is reduced, so the shape of the beading portion (114) may be deformed.

[0088] FIG. 5 is an enlarged cross-sectional view showing the beading portion (114) of a cylindrical secondary battery (1) and the second current collector plate (132) being welded together.

[0089] The second current collection plate (132) is connected to the second electrode non-removable portion (122) of the electrode assembly (10) and is also connected to the battery can (11) at the same time. The second current collection plate (132) includes a center (1321) formed flatly to support the electrode assembly (10) from above, a non-removable portion connecting portion (1322) formed extending outward from the center (1321) and arranged on the same plane as the center (1321) and connected to the second electrode non-removable portion (122) of the electrode assembly (10), a can connecting portion (1323) formed spaced outward from the center (1321) and connected to the battery can (11), and a bridge (1324) connecting the center (1321) and the can connecting portion (1323) to each other.

[0090] The central part (1321) is positioned above the electrode assembly (10) to support the electrode assembly (10) from above. The non-reinforced portion connecting part (1322) is formed in multiple numbers, extends outward from the central part (1321), and can be positioned on the same plane as the central part (1321). The multiple non-reinforced portion connecting part (1322) can be arranged in various forms without limitation, such as roughly radial or cross-shaped symmetrical forms centered on the central part (1321), or even asymmetrical forms. As described above, when the second electrode non-reinforced portion (122) protruding above the electrode assembly (10) is formed in the form of a segment, the multiple segments overlap each other to form a folded surface when bent, and the second electrode folded surface and the non-reinforced portion connecting part (1322) can be connected to each other by welding or the like. If the area of ​​the center (1321) is sufficiently wide, the second electrode bending surface may also be connected to the center (1321) by welding or the like.

[0091] The center (1321) and the non-electrode connecting portion (1322) are positioned approximately on the same plane and are connected to the second electrode bending surface of the second electrode non-electrode portion (122). Thus, they are positioned very close to the upper side of the electrode assembly (10) and can be located at the same height or lower than the lower surface of the beading portion (114) of the battery can (11).

[0092] The can connecting portions (1323) are formed in multiple numbers, spaced outward from the center (1321), and can be arranged around the center (1321). The multiple can connecting portions (1323) can be arranged in various forms without limitation, such as roughly radial or cross-shaped symmetrical forms centered on the center (1321), and furthermore, can be arranged in asymmetrical forms. Each of the multiple can connecting portions (1323) is spaced out along the periphery of the center (1321), and at least one can connecting portion (1323) can be formed between adjacent non-connecting portions (1322).

[0093] A plurality of can connecting portions (1323) each extend toward the inner side wall of the battery can (11), and in particular, if the battery can (11) includes a beading portion (114), they extend toward the beading portion (114). The can connecting portion (1323) is seated on the upper surface of the beading portion (114), and subsequently, the beading portion (114) and the can connecting portion (1323) are connected to each other by welding or the like. If the battery can (11) does not have a beading portion (114) or the depth of the beading portion (114) is very shallow, the can connecting portion (1323) of the second current collection plate (132) may be directly connected to the upper inner wall of the battery can (11) by welding or the like.

[0094] A bridge (1324) connects the center (1321) and the can connecting part (1323) to each other. These connecting parts may be formed in multiple numbers, such that they are formed in the same number as the multiple can connecting parts (1323). However, this is not limited thereto, and multiple bridges (1324) may connect a single can connecting part (1323) to the center (1321). As described above, the center (1321) is located at the same height as or lower than the lower surface of the beading part (114) of the battery can (11), while the can connecting part (1323) is seated on the upper surface of the beading part (114). That is, the center (1321) and the can connecting part (1323) are located at different heights. Since the bridge (1324) connects the center (1321) and the can connection (1323) located at different heights, the bridge (1324) may be in a shape that is inclined at a specific angle from the center (1321).

[0095] The non-electrode connecting portion (1322) and the can connecting portion (1323) are indirectly connected through the center (1321). That is, the second electrode non-electrode (122) and the non-electrode connecting portion (1322) are connected, and the non-electrode connecting portion (1322) is connected to the can connecting portion (1323) through the center (1321) and the bridge (1324), and the can connecting portion (1323) is connected to the battery can (11). Thus, the second electrode non-electrode (122) and the battery can (11) can be electrically connected to each other.

[0096] In the case of a conventional cylindrical secondary battery (1), a separate electrode tab or lead exists to connect the current collection plate (13) and the cap assembly, so the current collection plate (13) does not need to be seated on the upper surface of the beading portion (114), and there is no need to perform welding on the current collection plate (13) and the beading portion (114). However, in the case of a recently introduced tabless secondary battery (1), there is no electrode tab or lead, so in order to electrically connect the second current collection plate (132) to the battery can (11), welding must be performed on the can connection portion (1323) of the second current collection plate (132) and the beading portion (114) of the battery can (11).

[0097] Welding or the like can be performed to connect the can connection portion (1323) of the second current collector plate (132) and the beading portion (114) of the battery can (11) to each other, and for example, laser welding, ultrasonic welding, or spot welding may be applied. Among these, spot welding, which can be performed quickly and strongly on a thin metal member, is most preferred.

[0098] As illustrated in FIG. 5, when welding is performed, a weld bead (191) is formed in the weld area, leaving a trace of the weld. The weld bead (191) is formed between the can connection part (1323) and the beading part (114). If spot welding is performed once for each can connection part (1323), the weld bead (191) may be formed in a dot shape. However, if spot welding is performed several times for each can connection part (1323), the weld bead (191) may be formed in a specific pattern.

[0099] The defect of the weld can be determined based on the shape, size, and color of the weld bead (191). If the welding result is good, the bonding strength between the can connection part (1323) and the beading part (114) is improved, and a stable electrical connection can be secured. On the other hand, if the welding result is poor, the welding strength between the can connection part (1323) and the beading part (114) is reduced, so they can easily separate from each other even with a small impact. In addition, the resistance in the welding area becomes extremely high, preventing smooth electrical flow, and a large amount of heat may be generated in the welding area. Furthermore, as the internal airtightness of the battery can (11) weakens, a problem may occur where the electrolyte inside the battery can (11) leaks to the outside.

[0100] Therefore, it is necessary to perform an inspection to check for welding defects by analyzing the shape, size, and color of the weld bead (191) formed in the welding area between the can connection part (1323) and the beading part (114), and to do this, an inspection of the inside of the cylindrical battery can (11) must be performed before inserting the sealing gasket (18) and the can cover (17) into the battery can (11).

[0101] Meanwhile, when welding is performed, a back bead (192) may be formed on the opposite side of the weld area. A back bead (192) refers to a bead formed when a weld pool generated during welding melts and flows out to the opposite side of the weld area and solidifies. The defect of the weld can also be determined based on the shape, size, and color of such a back bead (192).

[0102] Therefore, it is necessary to perform an inspection to check for welding defects by analyzing the shape, size, and color of the back bead (192) formed on the opposite side of the welding area between the can connection part (1323) and the beading part (114), and to do this, an inspection of the exterior of the cylindrical battery can (11) must also be performed.

[0103] In this way, the weld bead (191) and the back bead (192) in the cylindrical battery can (11) are formed on the inside and outside of the battery can (11), respectively, in the same welding area where welding was performed. However, in the past, the inspection of the outside and the inspection of the inside of the cylindrical battery can (11) were performed separately, which was cumbersome as the inspection procedure had to be performed twice and took a long time. In addition, since two types of inspection modules, such as an external inspection module and an internal inspection module of the cylindrical battery can (11), had to be provided separately, the cost for installation and maintenance was high, and there was also a problem of the space inside the facility becoming cramped.

[0104] FIG. 6 is a planar perspective view of a secondary battery inspection device (2) according to one embodiment of the present invention, FIG. 7 is a bottom perspective view of a secondary battery inspection device (2) according to one embodiment of the present invention, and FIG. 8 is a bottom view of a secondary battery inspection device (2) according to one embodiment of the present invention.

[0105] A secondary battery inspection device (2) according to one embodiment of the present invention comprises: a plurality of first mirrors (21) formed radially, spaced apart from the central axis (X) of a body (20) by a first radius (r1); a plurality of second mirrors (22) formed radially, spaced apart from the central axis (X) by a second radius (r2) smaller than the first radius (r1); a plurality of prism mirrors (23) arranged in a direction facing each of the plurality of first mirrors (21) and the plurality of second mirrors (22) on the inner side of the plurality of first mirrors (21) and the plurality of second mirrors (22), and formed radially, spaced apart from the central axis (X) by a third radius (r3) smaller than the second radius (r2); and a light receiving unit (24) that receives light reflected through the prism mirrors (23).

[0106] According to the present invention, since the inspection of the exterior and interior of the battery can (11) of the secondary battery (1) can be performed in a single procedure using only one secondary battery inspection device (2), the inspection time and cost can be reduced and the space utilization within the facility can be increased.

[0107] The body (20) of the secondary battery inspection device (2) according to the present invention includes a first body (201) and a second body (202). The first body (201) includes a plurality of first mirrors (21), a plurality of second mirrors (22), and a prism mirror (23). The second body (202) may include a light receiving unit (24), but is not limited thereto, and the first body (201) may include a light receiving unit (24). Based on FIGS. 6 and 7, the first body (201) is a lower body (20) positioned downwards, and the second body (202) is an upper body (20) positioned upwards. However, the positions of the first body (201) and the second body (202) may change depending on the direction in which the secondary battery inspection device (2) is positioned.

[0108] A plurality of first mirrors (21) are formed radially at a first radius (r1) from the central axis (X) of the body (20), and are arranged in a so-called equal angle, which is repeated at regular angles around the central axis (X), as shown in FIG. 8. If four first mirrors (21) are formed, the plurality of first mirrors (21) are repeatedly arranged at 90° intervals around the central axis (X).

[0109] A plurality of second mirrors (22) are formed radially at a second radius (r2) from the central axis (X) of the body (20), and are arranged in a so-called equal angle, which is repeated at regular angles around the central axis (X), as shown in FIG. 8. If four second mirrors (22) are formed, the plurality of second mirrors (22) are repeatedly arranged at 90° intervals around the central axis (X).

[0110] The first radius (r1) and the second radius (r2) are different from each other, and in particular, the second radius (r2) is smaller than the first radius (r1). Therefore, the second mirror (22) is positioned closer to the central axis (X) of the body (20) than the first mirror (21). As described below, during the process of manufacturing a cylindrical secondary battery (1), the second current collector plate (132) is connected to the cylindrical battery can (11) by welding or the like, and the unfinished cylindrical secondary battery (1) is placed below the secondary battery inspection device (2) before the sealing gasket (18) and the can cover (17) are inserted into the cylindrical battery can (11). Then, the plurality of first mirrors (21) can face the outside of the cylindrical battery can (11), and the plurality of second mirrors (22) can face the inside of the cylindrical battery can (11).

[0111] A plurality of first mirrors (21) and a plurality of second mirrors (22) can be arranged alternately one by one. That is, one second mirror (22) can be arranged between two adjacent first mirrors (21), and one first mirror (21) can be arranged between two adjacent second mirrors (22). Also, a plurality of first mirrors (21) and a plurality of second mirrors (22) can be arranged equiangularly with respect to a central axis (X). If a total of eight first mirrors (21) and second mirrors (22) are formed, with four of each, the plurality of first mirrors (21) and the plurality of second mirrors (22) are arranged alternately one by one at 45° intervals.

[0112] A plurality of prism mirrors (23) are arranged on the inner side of a plurality of first mirrors (21) and a plurality of second mirrors (22) in a direction facing each of the plurality of first mirrors (21) and a plurality of second mirrors (22), and are arranged radially spaced apart from the central axis (X) by a third radius (r3). In particular, as shown in FIG. 8, they are arranged repeatedly at regular angles around the central axis (X), so-called equal angle arrangements. If eight plurality of prism mirrors (23) are formed, the plurality of prism mirrors (23) are repeatedly arranged at 45° intervals around the central axis (X).

[0113] The second radius (r2) and the third radius (r3) are different from each other, and in particular, the third radius (r3) is smaller than the second radius (r2). Therefore, the prism mirror (23) is positioned closer to the center axis (X) of the body (20) than the second mirror (22).

[0114] A plurality of prism mirrors (23) may be formed in a number equal to the sum of the number of a plurality of first mirrors (21) and a plurality of second mirrors (22). If a plurality of first mirrors (21) and a plurality of second mirrors (22) are each formed in 4 units, totaling 8 units, then a plurality of prism mirrors (23) may be formed in 8 units. A plurality of first mirrors (21) and a plurality of second mirrors (22) are arranged in a direction facing the central axis (X) of the body (20), but a plurality of prism mirrors (23) are arranged in a direction facing away from the central axis (X) of the body (20). Accordingly, a plurality of prism mirrors (23) may each be arranged in a direction facing one of a plurality of first mirrors (21) and a plurality of second mirrors (22).

[0115] FIG. 9 is a cross-sectional view taken along A-A' in FIG. 8, and FIG. 10 is a cross-sectional view taken along B-B' in FIG. 8.

[0116] According to one embodiment of the present invention, the secondary battery inspection device (2) can perform inspections on the exterior and interior of the cylindrical battery can (11) when the cylindrical secondary battery (1) is placed below it. During the process of manufacturing the cylindrical secondary battery (1), the second current collector plate (132) is connected to the cylindrical battery can (11) by welding or the like, and the cylindrical secondary battery (1) is placed below the secondary battery inspection device (2) before the sealing gasket (18) and the can cover (17) are inserted into the cylindrical battery can (11). Then, a plurality of first mirrors (21) can face the exterior of the cylindrical battery can (11), and a plurality of second mirrors (22) can face the interior of the cylindrical battery can (11).

[0117] As shown in FIG. 9, a plurality of first mirrors (21) face the outside of the cylindrical battery can (11) and reflect light incident from the outside of the cylindrical battery can (11) to the prism mirror (23), so that an image of the outside of the cylindrical battery can (11) is projected onto the plurality of first mirrors (21). In particular, a back bead (192) formed on the opposite side of the welding area between the can connection part (1323) and the beading part (114) may exist on the outside of the cylindrical battery can (11). Therefore, an image of the back bead (192) existing on the outside of the cylindrical battery can (11) is projected onto the plurality of first mirrors (21). To this end, the plurality of first mirrors (21) may be formed in a number equal to or greater than the number of can connection parts (1323) of the second current collection plate (132).

[0118] As shown in FIG. 10, a plurality of second mirrors (22) face the interior of the cylindrical battery can (11) and reflect light incident from the interior of the cylindrical battery can (11) to the prism mirror (23), so that an image of the interior of the cylindrical battery can (11) is projected onto the plurality of second mirrors (22). In particular, a weld bead (191) formed in the weld area between the can connection part (1323) and the beading part (114) may exist inside the cylindrical battery can (11). Therefore, an image of the weld bead (191) existing inside the cylindrical battery can (11) is projected onto the plurality of second mirrors (22). To this end, the plurality of second mirrors (22) may also be formed in a number equal to or greater than the number of can connection parts (1323) of the second current collection plate (132).

[0119] Accordingly, a plurality of first mirrors (21) and a plurality of second mirrors (22) may each be formed in a number equal to or greater than the number of can connection parts (1323) of the second current collection plate (132). If four can connection parts (1323) of the second current collection plate (132) are formed, then four or more first mirrors (21) and a plurality of second mirrors (22) may also each be formed.

[0120] Among the plurality of prism mirrors (23), an image of the outside of the cylindrical battery can (11) is projected onto a portion facing each of the plurality of first mirrors (21), and an image of the inside of the cylindrical battery can (11) is projected onto the remaining portion facing each of the plurality of second mirrors (22). The plurality of prism mirrors (23) reflect light incident from the plurality of first mirrors (21) and the plurality of second mirrors (22) to the light receiving portion (24).

[0121] The secondary battery inspection device (2) may further include a camera (not shown). In particular, among the bodies (20), the second body (202) may include a camera, and may be positioned above the light receiving unit (24) and positioned in a direction facing the light receiving unit (24). Such a camera may include an imaging element such as a CCD (Charge Coupled Device) or a CMOS (Complementary Metal-Oxide Semiconductor) image sensor.

[0122] The camera captures light incident on the light receiving unit (24) to generate an image of the secondary battery (1). When the camera transmits the generated image to a separate control unit (not shown), the control unit analyzes the size and shape of the weld bead (191) and back bead (192) of the secondary battery (1) through the image to determine whether there is a defect.

[0123] Meanwhile, a plurality of first mirrors (21) are formed with an inclination at a first angle of inclination (θ1) from the central axis (X), and a plurality of second mirrors (22) are formed with an inclination at a second angle of inclination (θ2) from the central axis (X). The first angle of inclination (θ1) and the second angle of inclination (θ2) may be the same as each other, but it is preferable that they be different, and in particular, the second angle of inclination (θ2) may be smaller than the first angle of inclination (θ1). By doing so, the plurality of first mirrors (21) and the plurality of second mirrors (22) can each face a more accurate direction in the cylindrical battery can (11).

[0124] A first body (201) may be formed with a control unit (25) for controlling the first radius (r1) and first inclination angle (θ1) of a plurality of first mirrors (21) and the second radius (r2) and second inclination angle (θ2) of a plurality of second mirrors (22). The control unit (25) is formed in multiple numbers, arranged at equal intervals along the outer surface of the first body (201), and one is positioned at each location corresponding to a plurality of first mirrors (21) and a plurality of second mirrors (22). Each first control unit (25) can control a plurality of first mirrors (21) and a plurality of second mirrors (22) individually.

[0125] One adjustment unit (25) may include a plurality of adjustment bolts. Preferably, two adjustment bolts are formed, and these two adjustment bolts are arranged one by one in the upper and lower directions. That is, the adjustment unit (25) includes an upper adjustment bolt (251) that moves the upper part of a plurality of first mirrors (21) or a plurality of second mirrors (22), and a lower adjustment bolt (252) that moves the lower part of a plurality of first mirrors (21) or a plurality of second mirrors (22).

[0126] When the upper adjustment bolt (251) positioned at the top is tightened, the upper adjustment bolt (251) moves gradually into the interior of the first body (201) and pushes out the upper portion of the first mirror (21) or the second mirror (22). Then, the first inclination angle (θ1) of the first mirror (21) or the second inclination angle (θ2) of the second mirror (22) increases. Conversely, when the lower adjustment bolt (252) positioned at the bottom is tightened, the lower adjustment bolt (252) moves gradually into the interior of the first body (201) and pushes out the lower portion of the first mirror (21) or the second mirror (22). Then, the first inclination angle (θ1) of the first mirror (21) or the second inclination angle (θ2) of the second mirror (22) decreases.

[0127] Meanwhile, when the upper adjustment bolt (251) positioned at the top is loosened, the upper adjustment bolt (251) gradually moves out of the interior of the first body (201) and pulls the lower part of the first mirror (21) or the second mirror (22). Then, the first inclination angle (θ1) of the first mirror (21) or the second inclination angle (θ2) of the second mirror (22) decreases. Conversely, when the lower adjustment bolt (252) positioned at the lower side is loosened, the lower adjustment bolt (252) gradually moves out of the interior of the first body (201) and pulls the lower part of the first mirror (21) or the second mirror (22). Then, the first inclination angle (θ1) of the first mirror (21) or the second inclination angle (θ2) of the second mirror (22) increases.

[0128] If both adjustment bolts are tightened, both adjustment bolts move slightly into the interior of the first body (201), causing the first radius (r1) of the first mirror (21) or the second radius (r2) of the second mirror (22) to decrease. Conversely, if both adjustment bolts are loosened, both adjustment bolts move slightly out of the interior of the first body (201), causing the first radius (r1) of the first mirror (21) or the second radius (r2) of the second mirror (22) to increase.

[0129] By adjusting the adjustment unit (25), the first radius (r1) and first inclination angle (θ1) of the first mirror (21), and the second radius (r2) and second inclination angle (θ2) of the second mirror (22) can be easily adjusted. Therefore, even if the size, shape, position, distance from the secondary battery inspection device (2), and the positions of the welding bead (191) and back bead (192) of the cylindrical battery can (11) change, the first radius (r1) and first inclination angle (θ1) of the plurality of first mirrors (21) and the second radius (r2) and second inclination angle (θ2) of the plurality of second mirrors (22) can be easily adjusted by the adjustment unit (25), thereby ensuring versatility.

[0130] The secondary battery inspection device (2) may further include a separate lighting unit (not shown). The lighting unit irradiates light toward the secondary battery (1) to be inspected. The light reflected from the secondary battery (1) is incident on each of the plurality of first mirrors (21) and the plurality of second mirrors (22). As a result, the image generated by the camera photographing the secondary battery (1) becomes brighter and clearer, allowing the welding bead (191) and back bead (192) of the secondary battery (1) to be inspected more quickly and accurately. The lighting unit may include an outer lighting unit that irradiates light toward the outside of the secondary battery (1) and an inner lighting unit that irradiates light toward the inside of the secondary battery (1). That is, by irradiating light separately toward the outside and inside of the secondary battery (1), the image of the secondary battery (1) can become brighter and clearer.

[0131] A secondary battery inspection device (2) according to one embodiment of the present invention may further include an actuator (not shown) that rotates a plurality of first mirrors (21) and a plurality of second mirrors (22) around the central axis (X) of the body (20). As described above, in a cylindrical battery can (11), a weld bead (191) and a back bead (192) are formed on the inside and outside of the battery can (11), respectively, in the same weld area where welding is performed. Then, a plurality of first mirrors (21) are directed toward the outside of the cylindrical battery can (11), so that an image of the outside of the cylindrical battery can (11) is projected onto the plurality of first mirrors (21), and a plurality of second mirrors (22) are directed toward the inside of the cylindrical battery can (11), so that an image of the inside of the cylindrical battery can (11) is projected onto the plurality of second mirrors (22). However, multiple first mirrors (21) and multiple second mirrors (22) are arranged at equal angles around the central axis (X) and positioned at positions spaced apart from each other by a predetermined angle. Therefore, when a secondary battery (1) is photographed using a single secondary battery inspection device (2), images of the inside and outside of the battery can (11) in different welding areas are generated. Then, a problem may arise in which the welding bead (191) and the back bead (192) in the same welding area cannot be photographed.

[0132] Accordingly, the actuator can rotate a plurality of first mirrors (21) and a plurality of second mirrors (22) by a predetermined angle at which adjacent first mirrors (21) and second mirrors (22) are spaced apart. For example, if a total of eight first mirrors (21) and second mirrors (22) are formed, with four of each, the adjacent first mirrors (21) and second mirrors (22) are spaced apart by 45° from each other around the central axis (X). Accordingly, after the camera captures an image of the cylindrical secondary battery (1) to generate a first image, the actuator rotates the plurality of first mirrors (21) and a plurality of second mirrors (22) by 45° around the central axis (X) of the body (20). That is, when the actuator rotates the plurality of first mirrors (21) and a plurality of second mirrors (22), the central axis (X) of the body (20) becomes the axis of rotation.

[0133] Then, the camera captures an image of the cylindrical secondary battery (1) to generate a second image. By doing so, the weld bead (191) and the back bead (192) formed in the same weld area on the cylindrical battery can (11) can be captured together. Then, the control unit can determine whether there is a welding defect by analyzing the first image and the second image.

[0134] The actuator may rotate the first body (201) while the second body (202) remains fixed. In this way, a plurality of first mirrors (21) and a plurality of second mirrors (22) formed on the first body (201) can rotate together with the first body (201). If the prism mirror is fixed to the first body (201), the prism mirror may rotate together with the first body (201) when the first body (201) rotates; however, if the prism mirror is fixed to the second body (202), the prism mirror may not rotate even if the first body (201) rotates.

[0135] Hereinafter, a method for inspecting a cylindrical battery can (11) of a cylindrical secondary battery (1) by a secondary battery inspection device (2) according to one embodiment of the present invention is described.

[0136] During the process of manufacturing a cylindrical secondary battery (1), an incomplete cylindrical secondary battery (1) is placed below a secondary battery inspection device (2) before the sealing gasket (18) and can cover (17) are inserted into the cylindrical battery can (11) after the second current collector plate (132) is connected to the cylindrical battery can (11) by welding or the like. Then, a plurality of first mirrors (21) can face the outside of the cylindrical battery can (11), and a plurality of second mirrors (22) can face the inside of the cylindrical battery can (11).

[0137] Light is incident on a plurality of first mirrors (21) from the outside of the cylindrical battery can (11). Then, an image of the outside of the cylindrical battery can (11) is projected onto the plurality of first mirrors (21), and in particular, an image of the back bead (192) formed on the outside of the cylindrical battery can (11) is projected. Meanwhile, light is incident on a plurality of second mirrors (22) from the inside of the cylindrical battery can (11). Then, an image of the inside of the cylindrical battery can (11) is projected onto the plurality of second mirrors (22), and in particular, an image of the weld bead (191) formed on the inside of the cylindrical battery can (11) is projected.

[0138] A plurality of first mirrors (21) and a plurality of second mirrors (22) reflect light incident from the outside and inside of the cylindrical battery can (11) to the prism mirrors (23). An image of the outside of the cylindrical battery can (11) is projected onto a portion of the plurality of prism mirrors (23) that faces each of the plurality of first mirrors (21), and an image of the inside of the cylindrical battery can (11) is projected onto the remaining portion of the plurality of prism mirrors (23) that faces each of the plurality of second mirrors (22). The plurality of prism mirrors (23) reflect light incident from the plurality of first mirrors (21) and the plurality of second mirrors (22) to the light receiving unit (24). The camera can then capture images of the outside and inside of the cylindrical battery can (11) through the light receiving unit (24) to generate an image. The control unit analyzes the size and shape of the weld bead (191) and back bead (192) of the secondary battery (1) through an image to determine whether there is a defect.

[0139] FIG. 11 is a schematic diagram of a secondary battery inspection device (2) according to another embodiment of the present invention.

[0140] A secondary battery inspection device (2) according to one embodiment of the present invention includes an actuator to rotate a plurality of first mirrors (21) and a plurality of second mirrors (22). On the other hand, a secondary battery inspection device (2a) according to another embodiment of the present invention may include a pusher (26a) that is positioned below a body (20a) to support a cylindrical secondary battery (1) to be inspected from below, and rotates the cylindrical secondary battery (1) by rotating around the central axis (Xa) of the body (20a). The pusher (26a) can rotate the first mirror (21) and the second mirror (22) that are adjacent to each other by a predetermined angle of separation.

[0141] After connecting the second current collector plate (132) to the cylindrical battery can (11) by welding or the like, the unfinished cylindrical secondary battery (1) before inserting the sealing gasket (18) and the can cover (17) into the cylindrical battery can (11) is placed on the upper surface of the pusher (26a). The pusher (26a) rotates the cylindrical secondary battery (1) by rotating around the central axis (Xa) of the body (20a) after the camera (not shown) captures an image of the cylindrical secondary battery (1) to generate a first image. That is, when the pusher (26a) rotates the cylindrical secondary battery (1), the central axis (Xa) of the body (20a) becomes the axis of rotation. At this time, the central axis (Xa) of the body (20a) may coincide with the central axis of the pusher (26a) and may also coincide with the central axis of the cylindrical secondary battery (1).

[0142] According to another embodiment of the present invention, an actuator or pusher (26a) may not be separately provided.

[0143] Generally, multiple secondary batteries (1) are arranged in a line or in multiple columns and move continuously when undergoing various processes. The inspection process for the secondary batteries (1) is also performed when the secondary batteries (1) that have been moving continuously are positioned one by one in a specific area. However, if an actuator or pusher (26a) is provided separately and the actuator or pusher (26a) operates whenever the secondary batteries (1) are positioned one by one in a specific area, then all of the multiple secondary batteries (1) must stop each time, so it may take some more time to perform inspections on the numerous secondary batteries (1) in sequence.

[0144] Accordingly, according to another embodiment of the present invention, a plurality of first mirrors (21) and a plurality of second mirrors (22) may have a viewing angle greater than the angle separated from the first mirror (21) or second mirror (22) adjacent to each other.

[0145] For example, as described above, if a total of 8 first mirrors (21) and second mirrors (22) are formed, with 4 of each, the first mirrors (21) and second mirrors (22) are alternately arranged one by one at 45° intervals. That is, the first mirrors (21) and second mirrors (22) adjacent to each other are spaced 45° apart from each other around the central axis (X) and arranged at equal angles. However, if the viewing angle of each of the first mirrors (21) and second mirrors (22) is 45°, a problem may occur in which the weld bead (191) and the back bead (192) in the same weld area cannot be captured together.

[0146] At this time, the plurality of first mirrors (21) and the plurality of second mirrors (22) may each have a viewing angle of 50° to 90°, and preferably 60° to 70°. Thus, even if an actuator or pusher (26a) is not separately provided, the outside and inside of the same welded area where the weld bead (191) and the back bead (192) are formed together in the cylindrical battery can (11) can be projected together onto the plurality of first mirrors (21) and the plurality of second mirrors (22).

[0147] In order for the viewing angle of the plurality of first mirrors (21) and the plurality of second mirrors (22) to be greater than the angle of separation between adjacent first mirrors (21) or second mirrors (22), according to another embodiment of the present invention, the plurality of first mirrors (21) and the plurality of second mirrors (22) may be formed in various ways without limitation, such as being curved mirrors rather than flat mirrors.

[0148] A person skilled in the art to which the present invention pertains will understand that the present invention may be implemented in other specific forms without altering its technical concept or essential features. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims set forth below rather than by the detailed description above, and various embodiments derived from the meaning and scope of the claims and equivalent concepts should be interpreted as being included within the scope of the present invention.

[0149] [Explanation of the symbol]

[0150] 1: Secondary battery 2: Secondary battery inspection device

[0151] 10: Electrode assembly 11: Battery can

[0152] 12: Electrode non-electrode portion 13: Current collector plate

[0153] 14: Rivet terminal 15: Insulating gasket

[0154] 16: Insulator 17: Can cover

[0155] 18: Sealing gasket 20: Body

[0156] 21: 1st Mirror 22: 2nd Mirror

[0157] 23: Prism Mirror 24: Light Receiving Unit

[0158] 25: Control section 111: Bottom of the battery can

[0159] 112: Side of the battery can 113: Opening

[0160] 114: Bidding Section 115: Crimping Section

[0161] 121: First electrode unoccupied portion 122: Second electrode unoccupied portion

[0162] 131: First current collector plate 132: Second current collector plate

[0163] 141: Outer part of terminal 142: Inner part of terminal

[0164] 143: Terminal connection part 151: Gasket outer part

[0165] 152: Inner part of gasket 153: Gasket connection part

[0166] 171: Venting section 191: Weld bead

[0167] 192: Back bead 201: First body

[0168] 202: Second body 251: Upper adjustment bolt

[0169] 252: Lower adjustment bolt 1321: Center

[0170] 1322: Non-removable part connector 1323: Can connector connector

[0171] 1324: Bridge

[0172]

[0173]

Claims

1. A plurality of first mirrors formed radially, spaced apart from the central axis of the body by a first radius; A plurality of second mirrors formed radially, spaced apart from the central axis by a second radius smaller than the first radius; A plurality of prism mirrors arranged radially on the inner side of the plurality of first mirrors and the plurality of second mirrors, facing each of the plurality of first mirrors and the plurality of second mirrors, and spaced from the central axis by a third radius smaller than the second radius; and A secondary battery inspection device comprising a light receiving unit that receives light reflected through the above-mentioned prism mirror.

2. In Paragraph 1, The above plurality of first mirrors are, They are arranged at equal angles around the above central axis, The above plurality of second mirrors are, A secondary battery inspection device arranged at equal angles around the above central axis.

3. In Paragraph 2, The plurality of first mirrors and the plurality of second mirrors are, Secondary battery inspection devices arranged alternately one by one.

4. In Paragraph 3, The plurality of first mirrors and the plurality of second mirrors are, A secondary battery inspection device arranged equidistantly around the central axis.

5. In Paragraph 1, The above plurality of prism mirrors are, A secondary battery inspection device arranged at equal angles around the above central axis.

6. In Paragraph 1, The above plurality of prism mirrors are, A secondary battery inspection device formed with a number equal to the sum of the number of the plurality of first mirrors and the plurality of second mirrors.

7. In Paragraph 6, The above plurality of prism mirrors are, A secondary battery inspection device, each arranged facing one of the plurality of first mirrors and one of the plurality of second mirrors.

8. In Paragraph 1, A secondary battery inspection device further comprising a camera positioned in a direction toward the light receiving unit and capturing light incident on the light receiving unit.

9. In Paragraph 1, The above plurality of first mirrors are, It is formed with a first angle of inclination from the above central axis, and The above plurality of second mirrors are, A secondary battery inspection device formed with a second angle of inclination smaller than the first angle of inclination from the above central axis.

10. In Paragraph 9, A secondary battery inspection device further comprising a control unit for adjusting the first radius, the first inclination angle, the second radius, and the second inclination angle.

11. In Paragraph 10, The above adjustment unit is, An upper adjustment bolt for moving the upper portion of the plurality of first mirrors or the plurality of second mirrors; and A secondary battery inspection device comprising a lower adjustment bolt that moves the lower portion of the plurality of first mirrors or the plurality of second mirrors.

12. In Paragraph 1, A secondary battery inspection device further comprising an actuator that rotates the plurality of first mirrors and the plurality of second mirrors around the central axis of the body.

13. In Paragraph 12, The above actuator is, A secondary battery inspection device that rotates the plurality of first mirrors and the plurality of second mirrors by an angle at which the first mirror and the second mirror adjacent to each other are separated.

14. In Paragraph 1, A secondary battery inspection device that supports a secondary battery to be inspected from below and further includes a pusher that rotates around the central axis of the body.

15. In Paragraph 14, The above pusher is, A secondary battery inspection device in which the first mirror and the second mirror adjacent to each other rotate by an angle of separation.

16. In Paragraph 1, The plurality of first mirrors and the plurality of second mirrors are, A secondary battery inspection device having a viewing angle greater than the angle separated from the first mirror or the second mirror adjacent to each other.

Images