Apparatus for welding current collectors and method of welding current collectors

Abstract

An apparatus for welding current collectors and a method of welding current collectors are disclosed. The apparatus for welding current collectors comprises: an offset detector for detecting a center offset, which is the deviation between a set reference position and the electrode center position of a cylindrical electrode assembly extending in the axial direction; a current collector coupler, which temporarily couples a current collector to the electrode assembly at a coupling position at which a current collection center position and the electrode center position are aligned, by moving, in parallel, by the center offset, the current collector disposed such that the current collection center position is aligned at an initial position spaced a coupling gap from a reference position in the transfer direction of the electrode assembly; and a current collector welder, which welds the temporarily coupled current collector to the electrode assembly so as to permanently couple same. Eccentricity defects of a welded electrode body can be prevented.

Description

Collector plate welding device and collector plate welding method

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0090574, dated July 9, 2024, and Korean Patent Application No. 10-2025-0091157, dated July 7, 2025, the entire contents of which are incorporated herein by reference.

[0002] The present disclosure relates to a collector plate welding device and a collector plate welding method using the same, and more specifically, to a large-capacity collector plate welding device that automatically welds a collector plate and an electrode assembly for a large-capacity secondary battery, and a collector plate welding method using the same.

[0003] Secondary batteries typically contain a cathode, anode, and an electrolyte, and generate electrical energy through chemical reactions. Their use is steadily increasing due to their ability to be recharged and discharged. Among these secondary batteries, lithium secondary batteries boast a high energy density per unit weight, making them widely used as power sources for electronic communication devices and as power sources for high-power hybrid and electric vehicles.

[0004] Cylindrical secondary batteries include a can housing and an electrode assembly. The can housing is manufactured by deep-drawing a metal sheet to form a circular bottom portion and a circular tubular side wall member connected thereto. The electrode assembly is formed into a jelly-roll structure by winding a positive electrode, negative electrode, and separator in a laminated state.

[0005] Collector plates are bonded to each of the axial ends of the electrode assembly. A positive collector plate may be bonded to one end of the electrode assembly along the axial direction, and a negative collector plate may be bonded to the other end. For example, the collector plates are positioned so as to contact the foil at the end of the electrode assembly and then welded under pressure by a welding rod. The welding of the electrode assembly and collector plates as described above is typically performed automatically in an automatic welding facility.

[0006] At this time, if the centers of the electrode assembly and the collector plate do not coincide along the axial direction, the electrode weld formed after welding will have an inherent eccentricity defect.

[0007] When forming electrode assemblies into a jelly-roll structure, the density distribution and shape uniformity of the electrode assemblies may vary slightly depending on process characteristics, such as the applied tension and the distribution of the roll weight. Consequently, the geometric center of the electrode assembly will vary slightly from one electrode assembly to another, depending on the degree of uniformity in mass distribution.

[0008] Therefore, if the electrode assembly and the collector plate are uniformly welded at the joint location of the welding equipment without axial alignment of the electrode assembly and the collector plate, an eccentric defect occurs where the central axis of the electrode assembly and the central axis of the collector plate do not align. Since it is difficult to perform sufficient welding on the eccentric collector plate and electrode assembly, the bonding stability of the collector plate and electrode assembly may decrease, and the yield of the secondary battery may decrease.

[0009] Misalignment of the electrode assembly and the current collector plate also causes misalignment with respect to the central axis of the battery can housing the electrode assembly, resulting in interference between either the current collector plate or the electrode assembly and the battery can when the electrode assembly is inserted into the can housing. Consequently, the overall process efficiency of the secondary battery is reduced.

[0010] In particular, in the case of large-sized batteries or energy storage systems (ESS), the size of eccentricity defects cannot be ignored, and has a significant impact on the stability and yield of secondary batteries.

[0011] Accordingly, a new collector plate welding device and a collector plate welding method using the same are required, which can automatically perform axial alignment to match the center positions of the electrode assembly and the collector plate before performing welding.

[0012] The background technology of the present invention is disclosed in Korean Patent Publication No. 2023-0067488 (published on May 16, 2023, title of the invention: Jig for supporting electrode assembly and current collector plate, welding method using the same, welding equipment using the method).

[0013] The present invention has been proposed to solve the above-described problem, and an object of the present invention is to provide a collector plate welding device capable of automatically aligning the collector plate and the electrode assembly along the axial direction before performing welding to eliminate eccentricity defects of the collector plate and the electrode assembly.

[0014] Another object of the present invention is to provide a current collector welding method for automatically aligning an electrode assembly and a current collector plate and then welding them using the current collector welding device described above.

[0015] The technical objectives of the present invention are not limited to the purposes mentioned above. Other objectives and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0016] Conventional collector plate welding devices uniformly weld electrode assemblies and collector plates at set positions, ignoring individual center deviations of cylindrical electrode assemblies, which increases yield reduction due to poor eccentricity of electrode welds.

[0017] In the present disclosure, before welding the electrode assembly and the collector plate, an offset detector that automatically detects the electrode center position, which is the center position of each electrode assembly, and a collector plate coupler that automatically aligns the collector center position, which is the center position of the collector plate, to the detected electrode center position are arranged so that eccentricity defects of the electrode weld body can be automatically prevented.

[0018] In order to achieve the above object, a current collector welding device according to one embodiment of the present disclosure may include an offset detector for detecting a center offset, which is a deviation between an electrode center position of a cylindrical electrode assembly extending along an axial direction and a set reference position, a current collector coupler for moving a current collector so that a current collector center position is aligned with an initial position spaced apart from the reference position by a coupling interval along a transport direction of the electrode assembly in parallel by the center offset, and temporarily coupling the current collector to the electrode assembly at a coupling position where the current collector center position and the electrode center position are aligned, and a current collector welder for permanently coupling the temporarily coupled current collector to the electrode assembly by welding it.

[0019] In one embodiment, the offset detector may include a profile generation module that is arranged to face the electrode assembly along the axial direction to generate a surface profile representing the shape of an end portion of the electrode assembly and displays the surface profile on a reference coordinate system having a reference position as an origin, a shape generation module that extracts three different points located on the surface profile, generates a virtual circle connecting the three points simultaneously as a shape of the end portion, and detects the center of the virtual circle as the electrode center position, and an offset detection module that detects the coordinates of the electrode center position as a center offset in the reference coordinate system.

[0020] In one embodiment, the profile generation module may include a vision inspector having a reference monitor on which a reference coordinate system is displayed, and the virtual circle and electrode center positions may be configured to be displayed on the reference monitor.

[0021] As an example, the shape generation module and the offset detection module may be implemented as a shape generation algorithm and a detection algorithm and configured to be built into the offset detector.

[0022] As an example, the reference position may include the center position of a virtual circle for a sample assembly, which is a sample electrode assembly having the same geometric characteristics as the electrode assembly to be welded.

[0023] In one embodiment, the collector plate coupler may include a coupling rod that aligns the collector plate with the load center axis at an initial position and axially compresses the collector plate at the coupling position to couple the collector plate to an end of the electrode assembly, an alignment mount that couples the coupling rod to two-dimensionally move in response to a center offset within an alignment plane perpendicular to the axial direction to align the load center axis at the coupling position, and a rod driver that axially translates the coupling rod with the load center axis aligned at the coupling position to compress the collector plate to the electrode assembly.

[0024] As one embodiment, the collector plate coupler may further include a coupling jig having a circular disk shape corresponding to an end of the electrode assembly, a collector plate attached to one side, a coupling rod connected to the other side symmetrical to the one side, and detachably coupled to the electrode assembly by moving the coupling rod to couple the collector plate to the electrode assembly.

[0025] As one embodiment, the joining jig may be configured to have a plurality of welding openings symmetrically arranged from the center of the disk so that a joint portion, which is a portion of the current collector plate exposed through the welding openings, and an end portion of the electrode assembly are welded.

[0026] As one embodiment, the collector plate welder may be configured to apply either ultrasonic or laser energy through the welding aperture.

[0027] In one embodiment, the alignment mount may include an alignment column capable of moving the coupling load along a horizontal direction parallel to the transport direction and a vertical direction perpendicular to the axial direction and the horizontal direction, respectively, an alignment monitor displaying an alignment coordinate system which is a coordinate system that has an initial position as an origin and extends in the horizontal and vertical directions and is a coordinate system that is translated in parallel along the transport direction with a reference coordinate system, and a column driver that moves the alignment column along a center offset relative to the alignment coordinate system to align the center axis of the load aligned at the initial position at the coupling position.

[0028] In one embodiment, the column driver includes a horizontal drive unit that horizontally drives the alignment column to move the load center axis to a first drive position that is spaced horizontally from an initial position that is a center of the alignment coordinate system by a first component of the center offset, and a vertical drive unit that vertically drives the alignment column to move the load center axis to a second drive position that is spaced vertically from an initial position that is a center of the alignment coordinate system by a second component of the center offset, such that the engagement position can be determined as a coordinate of the alignment coordinate system having the first drive position and the second drive position.

[0029] As an example, the column driver may further include a load return unit that releases the coupling rod from the collector plate after the electrode assembly and the collector plate are coupled, and returns the coupling rod to the initial position so that the center axis of the load coincides with the initial position.

[0030] As one embodiment, the load return unit may be configured to control the horizontal drive unit and the vertical drive unit, respectively, to cause the alignment column to move in the reverse horizontal direction and the reverse vertical direction by a first component and a second component, respectively.

[0031] As one embodiment, the column driver may include an error comparison unit that compares the center offset with a stored tolerance and controls the alignment column to be driven only when the center offset is greater than the tolerance.

[0032] As one embodiment, the column driver may further include an alignment signal generating unit that generates an alignment completion signal when the load center axis is aligned with either the engagement position or the initial position.

[0033] As an example, the coupling rod may include any one of a hydraulic cylinder, a pneumatic cylinder, and an electric cylinder that linearly reciprocates along the axial direction.

[0034] As one embodiment, the apparatus further comprises at least one transport carrier movably coupled to a transport track provided as an infinite track, circulating along the transport track along a transport direction and carrying an electrode assembly, wherein an offset detector, a collector plate coupler, and a collector plate welder can be sequentially arranged along the transport direction at a position adjacent to the transport track.

[0035] In one embodiment, the transport carrier is movably fixed to the transport track and includes a support plate on which an electrode assembly is placed and a pair of grippers variably positioned on opposite peripheries of the support plate for securing or releasing the electrode assembly placed on the support plate so as to surround it, wherein the electrode assembly is positioned such that its axial direction is perpendicular to the transport direction and the offset detector, the collector plate coupler, and the collector plate welder can be positioned so as to face the electrode assembly.

[0036] As one embodiment, the collector plate coupler may include an anode coupler positioned at each end of the electrode assembly to couple a cathode collector plate to one end of the assembly and a cathode coupler positioned symmetrically to the other end of the electrode assembly, and the collector plate welder may include an anode welder positioned at each end of the electrode assembly to weld a cathode collector plate to one end and a cathode welder positioned at each end of the electrode assembly to weld a cathode collector plate to the other end.

[0037] In one embodiment, the collector plate couplers and collector plate welders may each be arranged in a plurality along a transport track, and the offset detector may include an offset transmission module that transmits the center offset to a corresponding coupler, which is a collector plate coupler positioned to face a corresponding carrier, which is a transport carrier on which an electrode assembly whose center offset is detected is mounted.

[0038] A method for welding a collector plate according to another embodiment of the present disclosure for achieving the above object may include a step of detecting a center offset, which is a deviation between an electrode center position of a cylindrical electrode assembly extending along an axial direction and a set reference position, a step of moving a collector plate arranged so that the current collector center position is aligned with an initial position spaced apart from the reference position along a moving direction of the electrode assembly in parallel by the center offset, and a step of temporarily joining the collector plate to the electrode assembly at a joining position where the current collector center position and the electrode center position are aligned, and a step of permanently joining the temporarily joined collector plate to the electrode assembly by welding it.

[0039] In one embodiment, the step of detecting the center offset may include the steps of generating a surface profile of an end of the electrode assembly from a surface image of the electrode assembly and displaying the surface profile on a reference coordinate system having a reference position as an origin, generating a virtual circle simultaneously connecting three different points located on an outermost circumference of the surface profile, and obtaining the center of the virtual circle as the electrode center position and detecting the coordinates of the electrode center position in the reference coordinate system as the center offset.

[0040] As an example, before detecting the center offset, the method may further include a step of setting the center of a virtual circle obtained from a surface profile of a sample assembly that is part of an electrode assembly to be welded as a reference position and a step of aligning the origin of the reference coordinate system with the reference position.

[0041] In one embodiment, the step of coupling the collector plate to the electrode assembly may include coupling the collector plate to a coupling rod such that the load center axis and the collector center position are aligned at an initial position, translating the coupling rod by a center offset within an alignment plane perpendicular to the axial direction to align the load center axis at the coupling position, and fastening the collector plate to an end of the electrode assembly by translating the coupling rod along the axial direction at the coupling position.

[0042] As one embodiment, the collector plate is fastened to one side of a coupling jig having a circular disk shape corresponding to an end of the electrode assembly, and the coupling rod is removably fastened to the other side of the coupling jig, so that the collector plate can be fastened to the coupling rod via the coupling jig.

[0043] In one embodiment, the step of aligning the load center axis at the engagement position may include defining an alignment coordinate system that is a coordinate system that has the initial position as an origin and extends in a horizontal direction parallel to the transport direction and in a vertical direction perpendicular to the axial direction and the horizontal direction, translating the engagement rod in a horizontal direction by a first component constituting the coordinate of the center offset from the initial position, and translating the engagement rod in a vertical direction by a second component constituting the coordinate of the center offset from the initial position.

[0044] As an example, the method may further include a step of returning the coupling rod to its initial position after attaching the current collector to the end of the electrode assembly.

[0045] As an example, the coupling load may only be moved to the coupling position if the center offset is greater than a tolerance.

[0046] According to the collector plate welding device and the collector plate welding method using the same according to an exemplary embodiment of the present invention, a unique electrode center position for each electrode assembly to be welded is detected by an offset detector, and then the collector plate coupler can automatically align the collector center position, which is the center of the collector plate, to the electrode center position.

[0047] Afterwards, the collector plate can be welded to the electrode assembly at a joint position where the electrode center position and the collector center position match, thereby significantly reducing the eccentricity defect of the electrode weld body.

[0048] Accordingly, the yield of a secondary battery including an electrode weldment and a battery module or battery pack including the same can be increased and the operating stability can be improved.

[0049] Additionally, if the collector plate bonding time is longer than the offset detection time, the process time in the collector plate bonding step can be shortened by increasing the number of collector plate couplers installed. Accordingly, the collector plate bonding time required for each electrode assembly becomes similar to the offset detection time, thereby reducing the welding process time.

[0050] Furthermore, if the welding time is longer than the offset detection time, the number of current collector welders installed can be increased to shorten the welding process time. Accordingly, the welding time required for each electrode assembly becomes approximately equal to the offset detection time of the electrode assembly, thereby reducing the welding process time.

[0051] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0052] The following drawings attached to this specification illustrate preferred embodiments of the present disclosure and, together with the detailed description of the invention described below, serve to further understand the technical idea of ​​the present disclosure, and therefore, the present disclosure should not be interpreted as being limited to matters described in such drawings.

[0053] FIG. 1 is a perspective view showing a current collector welding device according to one embodiment of the present disclosure.

[0054] Fig. 2 is a plan view showing the current collector welding device illustrated in Fig. 1.

[0055] Fig. 3 is a drawing showing in detail the transfer track of the current collector welding device illustrated in Fig. 1.

[0056] FIG. 4 is a cross-sectional view showing a transfer carrier provided in the current collector welding device illustrated in FIG. 1 according to one embodiment of the present disclosure.

[0057] FIG. 5 is a perspective view showing an electrode assembly according to one embodiment of the present disclosure.

[0058] Fig. 6 is a perspective view showing a laminate in which the electrode assembly illustrated in Fig. 5 is unfolded.

[0059] Fig. 7 is an exploded perspective view of the laminate illustrated in Fig. 6.

[0060] FIG. 8 is a drawing showing the configuration of an offset detector provided in the collector plate welding device illustrated in FIG. 1 according to one embodiment of the present disclosure.

[0061] FIG. 9 is a schematic diagram of a monitor of a vision inspection device with a reference coordinate system displayed according to one embodiment of the present disclosure.

[0062] FIG. 10 is a drawing showing an end of a sample assembly in which the center of the electrode is located at a reference position corresponding to the origin of the reference coordinate system illustrated in FIG. 9.

[0063] FIG. 11 is a drawing showing a state in which a surface profile representing the end shape of an electrode assembly is displayed in the reference coordinate system illustrated in FIG. 9 according to one embodiment of the present invention.

[0064] Figure 12 is a drawing showing a virtual circle and center offset corresponding to the surface profile shown in Figure 11.

[0065] FIG. 13 is a drawing showing an electrode assembly having an end shape corresponding to the virtual circle illustrated in FIG. 12.

[0066] Fig. 14 is a drawing showing a coupling jig according to one embodiment of the present disclosure.

[0067] Fig. 15 is a drawing showing the state of the coupling jig and the collector plate shown in Fig. 14.

[0068] Fig. 16 is a perspective view showing the process of joining a collector plate to an electrode assembly in the collector plate welding device illustrated in Fig. 1.

[0069] FIG. 17 is a drawing showing the configuration of a collector plate coupler that couples the collector plate illustrated in FIG. 16 to an electrode assembly according to one embodiment of the present disclosure.

[0070] Fig. 18 is a drawing showing an alignment coordinate system set on an alignment monitor equipped in a collector plate coupler illustrated in Fig. 17 and a coupling position displayed in the alignment coordinate system.

[0071] FIG. 19 is a flowchart illustrating a method of welding a collector plate to an electrode assembly using a collector plate welding device according to one embodiment of the present disclosure.

[0072] FIG. 20 is a flowchart illustrating a center offset detection process illustrated in FIG. 19 according to one embodiment of the present disclosure.

[0073] FIG. 21 is a flowchart showing a process of joining a current collector plate and an electrode assembly illustrated in FIG. 19 according to one embodiment of the present disclosure.

[0074] [Explanation of symbols]

[0075] 20: Electrode assembly 30: Collector plate 40: Joining jig 50: Electrode welder 100: Collector plate welding device 110: Transport track 120: Transport carrier 130: Feeder 140: Offset detector 150: Collector plate coupler 160: Collector plate welder 170: Discharge 180: Control unit Z1: First position Z2: Second position Z3: Third position Z4: Fourth position

[0076] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0077] The present invention is not limited to the embodiments disclosed below, but can be implemented in various forms and with various modifications. However, these embodiments are provided 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. Therefore, the present invention is not limited to the embodiments disclosed below, but should be understood to include all modifications, equivalents, and substitutes included within the technical spirit and scope of the present invention, as well as substitutions or additions of the components of one embodiment with those of another embodiment.

[0078] The attached drawings are merely intended to facilitate understanding of the embodiments disclosed in this specification, and should not be construed as limiting the technical ideas disclosed in this specification, but should be understood to encompass all modifications, equivalents, and substitutes included within the spirit and technical scope of the present invention. In the drawings, the components may be expressed in exaggerated sizes or thicknesses for ease of understanding, but the scope of protection of the present invention should not be construed as being limited thereby.

[0079] The terminology used in this specification is only used to describe specific implementations or examples and is not intended to limit the present invention. In addition, the singular expression includes the plural expression unless the context clearly indicates otherwise. In the specification, terms such as "comprises" and "consists of" are intended to indicate the presence of a feature, number, step, operation, component, part, or combination thereof described in the specification. In other words, it should be understood that terms such as "comprises" and "consists of" in the specification do not exclude in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0080] Terms that include ordinal numbers, such as first, second, etc., may be used to describe various components, but the components are not limited by these terms. These terms are used solely to distinguish one component from another.

[0081] When a component is referred to as being "connected" or "connected" to another component, it should be understood that it may be directly connected or connected to that other component, but that there may be other components intervening. Conversely, when a component is referred to as being "directly connected" or "connected" to another component, it should be understood that there are no other components intervening.

[0082] When a component is referred to as being "above" or "below" another component, it should be understood that it is not only positioned directly above that other component, but that there may also be other components present in between.

[0083] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with their meaning in the context of the relevant technology, and will not be interpreted in an idealized or overly formal sense unless explicitly defined herein.

[0084] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. In the present disclosure, the axial direction (z) represents the direction in which an imaginary axis passing through the center of a disk or cylinder shape extends, and the radial direction (r) represents a direction approaching (centripetal) or moving away (centrifugal) from the center of the disk or cylinder shape. In addition, the circumferential direction (θ) represents a direction surrounding an imaginary axis passing through the center of the disk or cylinder shape.

[0085] FIG. 1 is a perspective view showing a collector plate welding device according to one embodiment of the present disclosure, and FIG. 2 is a plan view showing the collector plate welding device illustrated in FIG. 1. FIG. 3 is a drawing showing in detail a transport track of the collector plate welding device illustrated in FIG. 1.

[0086] Referring to FIGS. 1 to 3, a current collector welding device (100) according to one embodiment of the present disclosure may include a transport carrier (120) that circulates along a transport track (110) and transports a cylindrical electrode assembly (20), an offset detector (140) that detects a center offset (CO of FIG. 12) which is a deviation between an electrode center position (ECP of FIG. 12) which is the center of the electrode assembly (20) and a set reference position (RP of FIG. 9), a collector plate coupler (150) that couples the collector plate (30) to the electrode assembly (20) by moving the collector plate (30) in parallel by the center offset (CO) so that the current collector center position (CCP of FIG. 16) and the electrode center position (ECP) are aligned, and a collector plate welder (160) that welds the collector plate (30) to the electrode assembly (20) to provide an electrode weldment (50).

[0087] As an example, the transport track (110) may be configured to form a closed loop as a transport line for transporting the electrode assembly (20) to be welded, and may be provided as an endless track. A transport carrier (120) may be coupled to the transport track (110), and the electrode assembly (20) may be mounted on the transport carrier (120) and transported along the transport track (110).

[0088] A supply end (130) for supplying a welding target electrode assembly (20) along a transport track (110), an offset detector (140) for detecting a center offset, a collector plate coupler (150) for temporarily connecting a collector plate (30) to the electrode assembly (20), a collector plate welder (160) for permanently connecting the collector plate (30) to the electrode assembly (20) by welding it, and a discharge end (170) for separating the electrode weldment (50) from the transport carrier (120) and discharging it to the outside may be arranged.

[0089] For example, the transport track (110) may include a support (111), a stator (112) arranged along the support (111), and a mover (113) movably coupled to the stator (112).

[0090] The support (111) is configured as a three-dimensional frame having a closed loop shape with an open space provided in the center and forming an infinite track, and the stator (112) may be configured as a plurality of rails arranged along the outer surface of the support (111). The mover (113) may move along the stator (112) and circulate around the perimeter of the support (111).

[0091] In the present embodiment, the stator (112) may include a linear rail on which a plurality of electromagnets are arranged, and the mover (113) may move along the stator by the magnetic force of the electromagnets.

[0092] In particular, one end of the mover (113) is fixed to a transfer carrier (120) arranged parallel to the upper surface of the support (111), and the other end is coupled to the outer surface of the support (111) so that it can move along the stator (112).

[0093] A plurality of movers (113) are movably connected to a support (111), and a transfer carrier (120) is individually fixed to each mover (113), so that the transfer carrier (120) can also be moved along with the movement of the mover (113).

[0094] As described below, since the electrode assembly (20) is mounted on the transport carrier (120), the electrode assembly (20) can be transported along the direction in which the mover (113) moves. That is, the direction of movement of the mover (113) can determine the transport direction of the electrode assembly (20).

[0095] By controlling the electromagnet constituting the stator (112) to change the direction of the magnetic force, the transport direction of the transport carrier (120), i.e., the transport direction of the electrode assembly (20), can be easily changed. Accordingly, the electrode assembly (20) can be transported along the periphery of the support (111) in the transport direction determined by the stator (112).

[0096] In this embodiment, a transport track (110) is disclosed that transports a mover (113) by magnetic force from an electromagnet, but this is exemplary, and the transport track (110) can be modified in various ways as long as the transport carrier (120) can move along the transport direction.

[0097] For example, the stator (112) may be a belt running in an endless loop, and the mover (113) may be provided as a support structure that is fixed to the belt and can support a transport carrier (120).

[0098] As an example, the transport carrier (120) may be provided as a carrier structure that is fixed by the mover (113) and moves together with the mover (113) and can accommodate the electrode assembly (20).

[0099] FIG. 4 is a cross-sectional view showing a transfer carrier provided in the current collector welding device illustrated in FIG. 1 according to one embodiment of the present disclosure.

[0100] Referring to FIG. 4, a transport carrier (120) according to one embodiment of the present disclosure may include a mount (121) capable of supporting an electrode assembly (20) and a gripper (123) coupled to a periphery of the mount to secure the electrode assembly (20).

[0101] The mount (121) is configured to be fixed to the mover (113) and transported together with the mover (113), and the electrode assembly (20) can be mounted in a receiving space defined by the mount (121) and a pair of grippers (122).

[0102] A spherical mounting groove (121a) is provided in the mount (121) so that an electrode assembly (20) is mounted thereon, and a pair of grippers (123) are arranged on opposite pairs of peripheral portions of the mount (121) so that the size of the accommodation space (S) therebetween can be adjusted by moving them away from or closer to each other.

[0103] In particular, the inner surface of the gripper (123) is provided with a concave portion (123a) arranged to correspond to the surface shape of the electrode assembly (20) having a cylindrical shape, thereby increasing the fixing stability for the electrode assembly (20).

[0104] Accordingly, electrode assemblies (20) of various sizes can be mounted in the receiving space (S) and stably fixed by the concave portion (123a) of the gripper (122).

[0105] The electrode assembly (20) can be mounted on a transport carrier (120) and transported along a transport track (110). Accordingly, an offset detector (140), a collector plate coupler (150), and a collector plate welder (160) are sequentially arranged around the transport track (110) to face the electrode assembly (20), so that center offset detection, alignment of the collector plate (30) and the electrode assembly (20), and welding of the collector plate (30) and the electrode assembly (20) can be sequentially performed for the electrode assembly (20) transported along the transport track (110).

[0106] For example, by arranging a supply terminal (130), an offset detector (140), a collector plate coupler (150), and a collector plate welder (160) at the first to fourth positions (Z1 to Z4) of the transport track (110), respectively, when the electrode assembly (20) mounted on the transport carrier (120) is transported along the transport track (110), a scheduled operation can be performed at the corresponding position, thereby manufacturing an electrode weldment (50) substantially free of eccentricity defects. The electrode weldment (50) on which the welding operation is completed can be separated from the transport carrier (120) and discharged to the outside through the discharge terminal (170).

[0107] The process of aligning the center position of the collector (CCP) and the center position of the electrode (ECP) and then welding the collector plate (30) to the electrode assembly (20) to eliminate eccentricity defects will be described in detail later.

[0108] Fig. 5 is a perspective view showing an electrode assembly according to one embodiment of the present disclosure, and Fig. 6 is a perspective view showing a laminate in which the electrode assembly shown in Fig. 5 is unfolded. Fig. 7 is an exploded perspective view showing the laminate shown in Fig. 6 in an exploded manner.

[0109] Referring to FIGS. 5 to 7, an electrode assembly (20) according to one embodiment of the present disclosure may have a cylindrical shape having a core cavity (CV) in the center by winding a laminate (20a) in which a first electrode (21) and a second electrode (22) are laminated with a separator (330) interposed therebetween in a jelly-roll structure.

[0110] For example, a first electrode (21), a separator (28), a second electrode (22), and a separator (28) may be sequentially stacked to form a stack (20a), and the stack (20a) may be wound around a core shaft to form a jelly-roll structure. Accordingly, the electrode assembly (20) may be provided in a cylindrical shape, and a core cavity (CV), which is an empty space, may be formed in the center. The first electrode (21) may be an anode, and the second electrode (22) may be a cathode. Of course, the opposite may also be the case.

[0111] The first electrode (21) and the second electrode (22) may be composed of a metal foil (23) and an electrode sheet in which an active material layer (24) is applied to the surface of the metal foil (23). The electrode sheet may have a holding portion (25) in which the active material layer (24) is applied and a non-conductive portion (26) in which the active material layer (24) is not applied.

[0112] The positive electrode sheet, which is an electrode sheet to which a positive electrode active material layer is applied, may have a non-conductive portion (26) arranged at one end along the sheet width corresponding to the height along the axial direction (z) of the electrode assembly (20), and the negative electrode sheet, which is an electrode sheet to which a negative electrode active material layer is applied, may have a non-conductive portion (26) arranged at the other end along the sheet width.

[0113] The non-conductive portion (26) may be exposed or protruded at an end of the sheet width in the laminate (20a). The non-conductive portion (26) itself functions as an electrode tab, so that the electrode assembly (20) can be provided with a tab-less structure that does not require a separate electrode tab.

[0114] The above-mentioned non-conductive portion (26) may be provided with notches at predetermined intervals to form a plurality of notched tabs (27) in the shape of flags. The plurality of notched tabs (27) may be arranged in a sawtooth shape along the length direction of the electrode sheet.

[0115] In this embodiment, each of the plurality of notching tabs (27) may have an equilateral trapezoidal shape. However, this is exemplary, and the notching tabs (27) may have various shapes such as a semicircle, a semi-ellipse, a triangle, a rectangle, a parallelogram, etc.

[0116] Additionally, in this embodiment, each notching tab (27) may have the same tab width along the longitudinal direction of the electrode sheet. However, this is exemplary, and the tab width of each notching tab (27) may be gradually or stepwise wider from the center to the periphery of the electrode sheet.

[0117] Additionally, in the present embodiment, the plurality of notching tabs (27) may have tab heights that gradually increase from the center to the periphery of the electrode sheet. However, this is exemplary, and the notching tabs (27) may have tab heights that are constant or gradually decrease.

[0118] In addition, in this embodiment, the notching tab (27) discloses a structure in which it is not arranged at a predetermined section at both ends along the longitudinal direction of the electrode sheet, but this is exemplary, and the notching tab (27) may not be arranged only at one end along the longitudinal direction of the electrode sheet.

[0119] In the jelly-roll type electrode assembly (20), the notched tabs (27) can be bent in the radial direction (r) and flattened. The notched tabs (27) can be bent inwardly in the radial direction (r) or outwardly. In the present embodiment, the notched tabs (27) can be bent inwardly in the radial direction (r) to form bent tabs (27a).

[0120] The above-mentioned bending tab (27a) can be formed by bending one by one during the process of forming a jelly-roll-shaped electrode assembly (20) by winding the laminate (20a). Alternatively, the above-mentioned bending tab (27) can be formed by bending all at once after winding the laminate (20a) to form a jelly-roll-shaped electrode assembly (20).

[0121] The bend tab (27a) of the first electrode (21) and the bend tab (27a) of the second electrode (22) that are bent and covered in the radial direction (r) can provide a plane that is substantially perpendicular to the axial direction (z) at both ends of the electrode assembly (20) in the axial direction (z).

[0122] A collector plate (30) can be joined to a bending tab (27a) having a substantially flat surface and positioned at both ends of an electrode assembly (20) by a collector plate coupler (150), and the collector plate (30) can be welded by a collector plate welder (160).

[0123] Referring again to FIGS. 1 to 3, a jelly-roll shaped electrode assembly (20) formed with a bending tab (27a) can be transported to and stored in a supply unit (130). The supply unit (130) can be provided as a storage structure that is arranged adjacent to the first location (Z1) and can store a plurality of electrode assemblies (20).

[0124] For example, the supply unit (130) may include a pickup device (not shown) that can individually extract stored electrode assemblies (20) and place them on a transport carrier (120). Electrode assemblies (20) manufactured in the electrode assembly line are stored in the supply unit (130) and can be individually extracted by the pickup device at a first position (z1) and placed on a transport carrier (120).

[0125] A transport carrier (120) equipped with an electrode assembly (20) can move along a transport direction (TD), and an empty carrier (120a) on which an electrode assembly (20) is not equipped can move to a first position (Z1). Accordingly, the electrode assembly (20) to be welded can be mounted on the transport carrier (120) moving along the transport track (110) at the first position (Z1) and supplied to the current collector welding process.

[0126] As an example, the offset detector (140) can detect a center offset, which is a deviation between the electrode center position of a cylindrical electrode assembly (20) extending along the axial direction (z) and a preset reference position (RP).

[0127] FIG. 8 is a drawing showing the configuration of an offset detector provided in the collector plate welding device illustrated in FIG. 1 according to one embodiment of the present disclosure.

[0128] Referring to FIG. 8, an offset detector (140) according to one embodiment of the present disclosure may include a profile generation module (141), a shape generation module (142), an offset detection module (143), and an offset transmission module (144).

[0129] For example, the profile generation module (141) can be arranged to face the electrode assembly (20) along the axial direction (z) to generate a surface profile regarding the end shape of the electrode assembly (20) and display the surface profile (SP) on a reference coordinate system (RC) having the reference position (RP) as the origin.

[0130] In the present embodiment, the profile generation module (141) may include a vision inspector (141a) that obtains a planar image of an end portion of an electrode assembly (20) and has a reference monitor (RM) on which a reference coordinate system (RC) is visually displayed, and an image processing processor (141b) that processes the planar image to generate a surface profile (SP) representing a rough end portion shape and displays the surface profile (SP) on a reference coordinate system (RC) having a reference position (RP) as an origin.

[0131] In particular, in this embodiment, the profile generation module (141) is disclosed as being singly arranged to face one end of the electrode assembly (20), but this is exemplary, and it may be arranged to face each of the two ends of the electrode assembly (20) to individually detect the electrode center position (ECP) at each end of the electrode assembly (20).

[0132] Accordingly, the electrode center position (ECP) can be individually detected at one end and the other end of the electrode assembly (20), and the current collector plate (30) having the current collector center position (CCP) aligned with each electrode center position (ECP) can be independently coupled.

[0133] The vision inspector (141a) can be positioned to face the electrode assembly (20) that is mounted on the transport carrier (120) in an area adjacent to the second position (Z2) of the transport track (110). Accordingly, a planar image of the surface shape of the end of the electrode assembly (20) can be obtained. The vision inspector (141a) can be equipped with multiple cameras.

[0134] For example, the vision inspector (141a) can irradiate light to the end of the electrode assembly (20) passing through the second position (Z2) and detect the light reflected from the end to obtain a planar image of the end.

[0135] In this embodiment, a single vision inspector (141a) is placed at the second position (Z2), but this is exemplary, and it is obvious that multiple vision inspectors (141a) may be placed if the accuracy of the surface profile (SP) can be increased.

[0136] The obtained planar image can be transmitted to an image processing processor (141b) to generate a surface profile (SP) representing the outline of the end portion of the electrode assembly (20). The planar image of the end portion is provided as a captured image having a plurality of bending tabs (27a) and a core cavity (CV), and the image processing processor (141b) can detect the outline of the planar image to obtain a surface profile (SP of FIG. 11) regarding the shape of the end portion.

[0137] In particular, the surface profile (SP) obtained by the image processing processor (141b) can be displayed on a reference monitor (RM) on which a reference coordinate system (RC) is arranged.

[0138] FIG. 9 is a schematic diagram of a monitor of a vision inspection device with a reference coordinate system displayed according to one embodiment of the present disclosure, and FIG. 10 is a diagram showing an end of a sample assembly with an electrode center positioned at a reference position corresponding to the origin of the reference coordinate system illustrated in FIG. 9.

[0139] Referring to FIGS. 9 and 10, a sample assembly (SA), which is an electrode assembly (20) randomly selected from among the electrode assemblies (20) to be welded, is loaded onto a transport carrier (120) and transported to a second position (Z2), and then the center of the sample assembly (SA) can be detected and set as a reference position (RP) in the same manner as detecting the electrode center position (ECP) described later.

[0140] That is, the reference position (RP) is set as the center position of any electrode assembly (20) having the average shape characteristics of the electrode assembly (20) on which the current collector (30) welding process is to be performed, and the electrode center position (ECP), which is the center of an individual electrode assembly (20) to be put into the actual welding process, can be indicated as an offset with respect to the set reference position (RP).

[0141] The vision inspector (141a) can generate a reference coordinate system (RC) whose origin is displayed at the center of the reference monitor (RM) using a built-in coordinate generation program. Accordingly, when the vision inspector (141a) is driven, the reference coordinate system can be automatically displayed on the reference monitor (RM) of the vision inspector (141a).

[0142] In the present embodiment, the reference coordinate system (RC) may be configured as a rectangular coordinate system having a first axis (x) and a second axis (y) that are displayed perpendicular to each other on the reference monitor (RM). Accordingly, each position of the surface profile (SP) displayed on the reference monitor (RM) can be specified as a two-dimensional coordinate by the reference coordinate system (RC).

[0143] At this time, before performing the welding process of the current collector (30) to the electrode assembly (20), a coordinate generation program can be driven to adjust the origin of the reference coordinate system (RC) to match the detected reference position (RP).

[0144] When the origin correction of the reference coordinate system (RC) to the reference position (RP) is completed, the center of the reference coordinate system (RC) shown in Fig. 9 and the center of the sample assembly (SA) shown in Fig. 10 can be located on the same line along the axial direction (z).

[0145] FIG. 11 is a drawing showing a state in which a surface profile representing an end shape of an electrode assembly is displayed in the reference coordinate system shown in FIG. 9 according to one embodiment of the present invention, and FIG. 12 is a drawing showing a virtual circle and a center offset corresponding to the surface profile shown in FIG. 11. FIG. 13 is a drawing showing an electrode assembly having an end shape corresponding to the virtual circle shown in FIG. 12.

[0146] Referring to FIGS. 11 to 13, when a surface profile (SP) regarding the end shape of an electrode assembly (20) is generated by an image processing processor (141b), a shape generation module (142) can randomly extract three different points (P1, P2, P3) located on the obtained surface profile (SP) and obtain a virtual circle (VC) that simultaneously connects the three extracted points (P1, P2, P3) as the end shape.

[0147] The shape generation module (142) can extract at least three points (P1, P2, P3) located differently along a surface profile (SP) and drive a shape generation algorithm to generate a virtual circle (VC) passing through the three points (P1, P2, P3) simultaneously. The shape generation algorithm can be implemented as an executable computer program and stored in the shape generation module (142).

[0148] At this time, the virtual circle (VC) may be a circle closest to the end shape of the electrode assembly (20) photographed at the second position (Z2). Accordingly, the center of the virtual circle (VC) may be set to the electrode center position (ECP), which is the actual center position of the individual electrode assembly (20).

[0149] In the same way, if the end photographed at the second position (Z2) is a sample assembly (SA), the center of the generated virtual circle (VC) can be set to the reference position (RP). That is, if three points are detected from the surface profile (SP) obtained from the sample assembly (SA) and a single sample virtual circle is generated by connecting the three extracted points, the center of the sample virtual circle can be set to the reference position (RP).

[0150] Accordingly, it can be evaluated that the further the electrode center position (ECP) is from the origin of the reference coordinate system (RC), the greater the deviation between the center of the individual electrode assembly (20) used in the collector plate welding process and the center of the sample assembly (SA). In other words, the distance between the electrode center position (ECP) and the origin of the reference coordinate system (RC) can be the center offset (CO) of the electrode assembly (20).

[0151] The offset detection module (143) can detect the deviation from the reference position (RP) to the electrode center position (ECP) and detect it as a center offset (CO). In the present embodiment, since the reference position (RP) is already set as the origin of the reference coordinate system (RC), the center offset (CO) can be directly extracted through the coordinates of the electrode center position (ECP). That is, the center offset (CO) can be obtained as a two-dimensional coordinate of the electrode center position (ECP) in the reference coordinate system (RC).

[0152] However, this is exemplary, and if the origin of the reference coordinate system (RC) does not coincide with the reference position (RP), the center offset (CO) can be obtained as a vector between the reference position (RP) and the electrode center position (ECP).

[0153] Similar to the shape generation module (142), the offset detection module (143) may include a detection algorithm for detecting a center offset (CO). The detection algorithm may be implemented as an executable computer program and stored in the offset detection module (143).

[0154] The offset transmission module (144) transmits a center offset (CO) to the collector plate coupler (150) so that the centers of the electrode assembly (20) and the collector plate (30) can be aligned within a set error range.

[0155] In particular, the offset transmission module (144) can be configured to ensure identity between the electrode assembly (20) in which the center offset (CO) is detected and the electrode assembly (20) to which the collector plate (30) is welded, when a plurality of collector plate couplers (150) are arranged.

[0156] The center offset (CO) is individually detected for every electrode assembly (20) that reaches the second position (Z2) of the transfer track (110), so that it can be detected with different coordinates for each electrode assembly (20).

[0157] Therefore, when the collector plate welding process is performed on multiple electrode assemblies (20) at the same time, the center offset (CO) corresponding to the electrode assembly (20) to be welded can be transmitted to the corresponding collector plate coupler (150).

[0158] For example, the offset transmission module (144) can transmit the center offset (CO) to a corresponding coupler, which is a collector coupler (150) positioned to face a corresponding tray, which is a transfer tray (220) on which an electrode assembly (20) having a detected center offset (CO) is mounted. That is, the offset transmission module (144) can transmit the center offset (CO) separately for each transfer tray (220).

[0159] Referring back to FIGS. 1 to 3, the collector plate coupler (150) can couple the collector plate (30) to the electrode assembly (20) transferred to the third position (Z3). In particular, the collector plate coupler (150) can adjust the position of the collector plate (30) by the center offset (CO) transmitted from the offset detector (140) so that the center of the collector plate (30) is aligned with the center of the electrode assembly (20).

[0160] A current collector (30) is placed between an electrode assembly (20) in which electrical energy is stored and an electrode terminal connected to an external load that consumes electrical energy, so as to electrically connect the electrode assembly (20) and the electrode terminal.

[0161] Accordingly, the current collector plate (30) can be provided in various shapes depending on the shape and structure of the electrode assembly (20) and the electrode terminal. In the present embodiment, the current collector plate (30) can be provided with a first current collector plate (31) welded to a bend tab (27a) at one end of the cylindrical electrode assembly (20) and a second current collector plate (37) welded to the bend tab (27a) at the other end of the electrode assembly (20).

[0162] For example, the first collector plate (31) may be a positive collector plate connected to a positive electrode terminal, and the second collector plate (37) may be a negative collector plate connected to a battery can, which is a negative electrode terminal. The collector plate (30) may have a circular disk shape corresponding to the cylindrical electrode assembly and the cylindrical battery can.

[0163] In this embodiment, the collector plate (30) can be temporarily connected to the end of the electrode assembly (20) by a connecting jig (40).

[0164] FIG. 14 is a drawing showing a coupling jig according to one embodiment of the present disclosure, and FIG. 15 is a drawing showing a coupling state of the coupling jig and the collector plate shown in FIG. 14.

[0165] Referring to FIGS. 14 and 15, the joining jig (40) may be provided with a jig body (B) having a circular shape corresponding to the end shape of the electrode assembly (20) and having a welding opening (O) having a constant shape distributed therein. The jig body (B) is formed of a flat plate having a sufficient thickness and may be temporarily joined by pressing the current collector plate (30) to the end of the electrode assembly (20). A leg (L of FIG. 17) may protrude from the periphery of the jig body (B) and be attached to the periphery of the electrode assembly (20).

[0166] A plurality of welding openings (O) are symmetrically arranged to have the same shape so as to expose a current collector (30) arranged on one side of a jig body (B). Accordingly, the current collector (30) pressed by the jig body (B) and brought into close contact with an end of an electrode assembly (20) can be partially exposed through the plurality of welding openings (O).

[0167] The exposed area of ​​the collector plate (30) exposed through the welding opening (O) can be provided as a joint (34) on which welding is performed by a collector plate welder (160). That is, welding can be performed on the joint (34) through the welding opening (O) of the jig body (B).

[0168] In particular, the welding opening (O) can be configured to be larger than the joint (34) so ​​that welding can be stably performed on the joint (400) within the welding opening (O). If the welding opening (O) is smaller than the joint, welding may be performed only on a portion of the set joint (34), which may result in reduced welding stability.

[0169] In this embodiment, four welding openings (O) having the same shape and spaced apart from each other by 90° along the circumferential direction (θ) can be arranged on a jig body (B) provided as a circular flat plate.

[0170] As illustrated in Fig. 15, a current collector plate (30) may be placed on one side of a jig body (B), and a coupling rod (151 in Fig. 17) described later may be connected to the other side of the jig body (B). By the coupling rod (151), the coupling jig (40) may be pressed against the electrode assembly (20), thereby temporarily coupling the current collector plate (30) to an end of the electrode assembly (20).

[0171] When the collector plate (30) is connected to the end of the electrode assembly (20), the coupling rod (151) is retracted and the structure in which the collector plate (30) and the electrode assembly (20) are temporarily connected is transferred to the collector plate welder (160) to prepare for welding.

[0172] At this time, the collector plate (30) is attached so that its central axis aligns with the coupling jig (40), and the coupling rod (151) is also connected so that its central axis aligns with the coupling jig (40), so that the collector plate (30), the coupling jig (40), and the coupling rod (151) can be arranged so that their central axes align with each other.

[0173] FIG. 16 is a perspective view showing a process of joining a collector plate to an electrode assembly in the collector plate welding device shown in FIG. 1, and FIG. 17 is a drawing showing a configuration of a collector plate coupler that joins the collector plate shown in FIG. 16 to an electrode assembly according to one embodiment of the present disclosure.

[0174] Referring to FIGS. 16 and 17, a collector plate coupler (150) according to one embodiment of the present disclosure may include a coupling rod (151) that fixes a collector plate (30) and presses it along the axial direction (z), an alignment mount (152) that aligns the collector plate (30) at a coupling position, and a load driving unit (153) that drives the coupling rod (151) to move it.

[0175] For example, the coupling rod (151) may be formed of a hydraulic or pneumatic cylinder structure having sufficient strength and rigidity, and may be coupled to the collector plate (30) at one end and to the alignment mount (152) at the other end. Accordingly, the coupling rod (151) may be linearly moved along the axial direction (z) to advance toward the electrode assembly (20) or to retreat from the electrode assembly (20).

[0176] At this time, the load center axis (151s) of the coupling rod (151) may be positioned to align with the initial position (IP), and the collector plate (30) may be fixed such that the collector center position (CCP) is aligned with the load center axis (151s). Accordingly, before the welding process is performed, the coupling rod (151) may be aligned with the initial position (IP), and the collector plate (30) may be fixed such that the centers of the coupling rod (151) are aligned with each other.

[0177] In the present embodiment, the initial position (IP) can be set to a position spaced apart from the reference position (RP) detected at the second position (Z2) by the coupling gap, which is the distance between the third position (Z3) where the current collector welding process is performed and the second position (Z2). That is, the initial position (IP) can be set to a position spaced apart from the reference position (RP) by the coupling gap along the transfer track (110).

[0178] Therefore, before the welding process is performed, the collector plate (30) can be joined to the end of the joining rod (151) so that the load center axis (151s) and the collector center position (CCP) are aligned with each other at the initial position (IP).

[0179] In the present embodiment, the collector plate (30) can be fastened to the coupling rod (151) via the coupling jig (40). The collector plate (30) is fastened to the center of the coupling jig (40) to form a jig assembly (40s), and the jig assembly (40s) is detachably fastened to the end of the coupling rod (151) at the initial position (IP).

[0180] For example, the alignment mount (152) can be placed at the other end of the coupling rod (151) to shift the coupling rod (151) from the initial position (IP) to the coupling position (CP) or from the coupling position (CP) to the initial position (IP).

[0181] That is, the alignment mount (152) can move the coupling rod (151) in parallel within the alignment plane perpendicular to the axial direction (z) so that the current collector plate (30) (in this embodiment, the jig assembly (40s)) can move the current collector center position (CCP) to the reference position (RP) and the coupling position (CP). Therefore, if the coupling rod (151) can move in parallel within the alignment plane, the alignment mount (152) can be configured with various structures.

[0182] In the present embodiment, the alignment mount (152) may include an alignment column (152a) that transports the coupling load (151), an alignment monitor (AM) that displays an alignment coordinate system (AC) and a center position of the current collector (CCP) and an electrode center position (ECP), and a column driver (152b) that two-dimensionally drives the alignment column (152a) to align the center axis of the load (151s) to the coupling position (CP).

[0183] For example, the alignment column (152a) may be configured as a column structure connected to a coupling rod (151) to enable two-dimensional movement within an alignment plane. The alignment column (152a) may extend upward from a base (not shown) and may be connected to the coupling rod (151) at a coupling end provided at an upper end. For example, the alignment column (152a) may move along a horizontal direction (HD) parallel to the transport direction (TD) relative to the base, and the coupling end may move the coupling rod (151) along an axial direction (z) and a vertical direction (VD) perpendicular to the horizontal direction (HD).

[0184] Accordingly, the alignment column (152a) can move the coupling load (151) along the horizontal direction (HD) and the vertical direction (VD) to align the load center axis (151s) aligned at the initial position with the coupling position (CP).

[0185] At this time, the coupling position (CP) can be determined by the center offset (CO) transmitted from the offset detector (140). The column driver (152b) can drive the alignment column (152a) to move by extracting the movement distance of the alignment column (152a) in the horizontal direction (HD) and the vertical direction (VD) by the transmitted center offset (CO).

[0186] Accordingly, the coupling load (151) aligned with the initial position (IP) can be moved to align with the coupling position (CP) by the alignment mount (152).

[0187] In this embodiment, movement of the coupling load (151) from the initial position (IP) to the coupling position (CP) can be performed using the alignment coordinate system (AC).

[0188] Fig. 18 is a drawing showing an alignment coordinate system set on an alignment monitor equipped in a collector plate coupler illustrated in Fig. 17 and a coupling position displayed in the alignment coordinate system.

[0189] Referring to FIG. 18, the alignment monitor (AM) is connected to the alignment column (152a) and the coupling load (151) so as to display the position of the coupling load (151) on the alignment coordinate system (AC).

[0190] An initial position (IP) is determined to be spaced apart from a reference position (RP) by a coupling interval along a transport direction (TD), and a coordinate system having the initial position (IP) as an origin and axes extending in the horizontal direction (HD) and vertical direction (VD) can be created as an alignment coordinate system (AC).

[0191] The alignment coordinate system (AC) can be displayed on the alignment monitor (AM) and can serve as a reference for specifying the position when the alignment mount (152) moves the coupling load (151).

[0192] The jig assembly (40s) is coupled to the end of the coupling rod (151) so as to be aligned with the load center axis (151s), and the load center axis (151s) is configured to be positioned at the initial position (IP). Accordingly, the center position (CCP) of the current collector plate (30) coupled to the jig assembly (40s) can be aligned with the initial position (IP) and coupled to the coupling rod (151).

[0193] When the center offset (CO) is transmitted from the offset detector (140) to the column driver (152b), the column driver (152b) can obtain the movement distance of the alignment column (152a) along the horizontal direction (HD) and the vertical direction (VD) from the center offset (CO).

[0194] Since the first direction (D1) and the second direction (D2) of the reference coordinate system (RC) are substantially the same directions as the horizontal direction (HD) and the vertical direction (VD) of the alignment coordinate system (AC), the alignment coordinate system (AC) can be viewed as a reference coordinate system (RC) whose origin has been moved parallel from the reference position (RP) to the initial position (IP). Accordingly, the center offset (CO), which is the deviation from the reference position (RP) to the electrode center position (ECP), can represent the deviation from the initial position (IP) to the electrode center position (ECP).

[0195] That is, the deviation between the center of the welding target electrode assembly (20) and the initial position (IP) at the third position (Z3) becomes substantially equal to the center offset (CO) detected at the second position (Z2).

[0196] Therefore, when the position of the coupling rod (151) aligned to the initial position (IP) is moved by a center offset (CO) from the initial position (IP), it substantially coincides with the electrode center position (ECP) of the electrode assembly (20) to be welded.

[0197] Since the reference coordinate system (RC) is a two-dimensional planar coordinate system, the center offset (CO) is detected as a two-dimensional coordinate, and each component of the center offset (CO) in the alignment coordinate system (AC) represents the distance that the center position (CCP) aligned with the initial position (IP) will move along the horizontal direction (HD) and the vertical direction (VD) to align with the electrode center position (ECP).

[0198] That is, the position of the coupling rod (151) can be adjusted so that the load center axis (151s) is aligned with the electrode center position (ECP) by moving the fixed coupling rod (151) on the alignment plane by a center offset (CO) so that the current collection center position (CCP) is aligned with the load center axis (151s). Accordingly, the current collection plate (30) can be positioned at the coupling position (CP) where the current collection center position (CCP) and the electrode center position (ECP) are aligned with each other.

[0199] The column driver (152b) may include a horizontal drive unit (1521) that moves the alignment column (152a) in the horizontal direction (HD) by a first component of the transmitted center offset (CO) and a vertical drive unit (1522) that moves the alignment column (152a) in the vertical direction (VD) by a second component of the center offset (CO).

[0200] Accordingly, the coupling load (151) can be shifted such that the load center axis (151s) is positioned at a first driving position along the horizontal direction (HD) from the initial position (IP) and at a second driving position along the vertical direction (VD). That is, the coupling load (151) can be positioned at a coupling position (CP) having the first driving position and the second driving position as components along the horizontal direction (HD) and the vertical direction (VD) in the alignment coordinate system (AC).

[0201] Since the electrode center position (ECP) of the electrode assembly (20) is located at a distance from the reference position (RP), which is the origin in the reference coordinate system (RC), by the center offset (CO), the electrode center position (ECP) of the electrode assembly (20) is located at a distance from the initial position (IP), which is the origin in the alignment coordinate system (AC), by the center offset (CO).

[0202] Therefore, the current collecting center position (CCP) of the current collecting plate (30) at the coupling position (CP) is aligned with the electrode center position (ECP) of the electrode assembly (20) along the axial direction (z).

[0203] Preferably, the column driver (152b) may be provided with an error comparison unit (1523) that controls the alignment column (152a) to be driven only when the center offset (CO) is greater than the tolerance by comparing the center offset (CO) with a stored tolerance.

[0204] If the eccentricity defect can be ignored even if the electrode center position (ECP) and the collector center position (CCP) are not aligned exactly on a single line, there is no need to move the coupling rod (151) to perform center alignment of the collector plate (30) and the electrode assembly (20).

[0205] Accordingly, when the center offset (CO) is transmitted from the offset detector (140), the error comparison unit (1521) can selectively adjust the operation of the alignment mount (152) by comparing the center offset (CO) with the stored tolerance.

[0206] When the center offset (CO) is smaller than the allowable error, the deviation between the electrode center position (ECP) of the electrode assembly (20) to be welded and the current collector center position (CCP) of the current collector (30) is sufficiently small, so that current collector welding can be performed at the initial position (IP) without adjusting the position of the joining rod (151).

[0207] In contrast, if the center offset (CO) is larger than the allowable error, there is a risk of eccentricity failure due to a large deviation between the electrode center position (ECP) of the electrode assembly (20) to be welded and the current collector center position (CCP) of the current collector plate (30), so the joining rod (151) is forcibly moved to the joining position (CP) to align the electrode center position (ECP) and the current collector center position (CCP), and then welding of the current collector plate is performed.

[0208] Accordingly, the driving efficiency of the collector plate coupler (150) can be increased by selectively controlling the driving of the alignment mount (152).

[0209] In addition, the column driver (152b) may be equipped with a separate alignment signal generation unit (1524). When the shift operation of the load center axis (151s) by the center offset (CO) is completed by the column driver (152b), the alignment signal generation unit (1524) may generate an alignment completion signal and transmit it to the load driver (153).

[0210] According to the alignment completion signal, the load driving unit (153) can move the coupling load (151) along the axial direction (z) to fasten the jig assembly (40s) having the current collector (30) to the end of the electrode assembly (20).

[0211] For example, the coupling rod (151) may be configured as one of a pneumatic, hydraulic or electric cylinder, and the rod drive unit (153) may be configured as a power source capable of supplying pneumatic, hydraulic or electric power to the coupling rod (151).

[0212] The jig assembly (40s) can be pressed against the electrode assembly (20) by the transfer of the coupling rod (151). The pressed jig assembly (40s) is fastened to the electrode assembly (20) through the leg (L), and the collector plate (30) is pressed to the end by the jig body (B).

[0213] When the jig assembly (40s) is fastened to the end of the electrode assembly (20), the fastening of the coupling rod (151) and the jig body (B) is released, thereby completing the collector plate fastening process. Thereafter, the electrode assembly (20) to which the jig assembly (40s) is fastened is moved to the fourth position (Z4) and the collector plate welding process is performed.

[0214] When the coupling rod (151) and the jig assembly (40s) are released, the electrode assembly (20) can be retracted along the axial direction (z) and the coupling rod (151) can be returned to the initial position (IP) through the load return unit (1525).

[0215] For example, the load return unit (1525) can be configured to control the horizontal drive unit (1521) and the vertical drive unit (1522), respectively, so that the alignment column (152a) moves in the reverse horizontal direction and the reverse vertical direction by the first component and the second component, respectively.

[0216] Accordingly, the coupling load (151) can be shifted from the coupling position (CP) to the initial position (IP). That is, the load center axis (151s) aligned along the coupling position (CP) is aligned again along the initial position (IP).

[0217] The current collector (30) may include a positive current collector (31) and a negative current collector (37) having different electrical polarities. The positive current collector (31) may be welded to a positive electrode bending tab (27a) arranged at one end of the electrode assembly (20), and the negative current collector (37) may be welded to a negative electrode bending tab (27a) arranged at the other end of the electrode assembly (20).

[0218] Accordingly, the collector plate coupler (150) may be composed of a pair of positive and negative collector plates (CP1, CN1) for coupling the positive and negative collector plates (31, 37). The positive collector (CP1) may be positioned adjacent to one end of the electrode assembly (20) at a third position (z3), and the negative collector (CN1) may be positioned adjacent to the other end of the electrode assembly (20) at a third position (z3).

[0219] Referring again to FIGS. 1 to 3, the collector plate welder (160) can perform welding on the collector plate (30) whose center alignment is completed along the axial direction (z) by being positioned so as to face the electrode assembly (20) at a position adjacent to the fourth position (Z4) of the transport track (110). Accordingly, the collector plate (30) can be permanently fixed to the electrode assembly (20).

[0220] When the fastening of the jig assembly (40s) to the electrode assembly (20) is completed at the third position (Z3), the transfer tray (220) moves to the fourth position (Z4) so ​​that welding of the current collector (30) and the electrode assembly (20) can be performed.

[0221] For example, a collector plate welder (160) positioned to face the electrode assembly (20) can weld the joint (34) of the collector plate (30) exposed through the welding opening (O) of the jig assembly (40s) and secure it to the bending tab (27a) of the electrode assembly (20).

[0222] In this embodiment, the collector plate welder (160) may include a laser welder or an ultrasonic welder that performs welding by applying a laser or ultrasonic waves to the joint (34) through a welding opening (O).

[0223] In particular, the collector plate welder (160) may have different configurations depending on the properties of the bend tab (27a) and the collector plate (30). Accordingly, the collector plate welder (160) may include a positive electrode welder (WP1) that welds the positive electrode collector plate (31) to the positive electrode bend tab (27a) and a negative electrode welder (WN1) that welds the negative electrode collector plate (37) to the negative electrode bend tab (27a).

[0224] The positive electrode welder (WP1) may be positioned adjacent to one end of the electrode assembly (20) at the fourth position (z4), and the negative electrode welder (WN1) may be positioned adjacent to the other end of the electrode assembly (20) at the fourth position (z4).

[0225] Depending on the configuration of the welding device (100), the supply terminal (130), the collector plate coupler (150), and the collector plate welder (160) may be arranged singly or in multiples. When the supply terminal (130), the collector plate coupler (150), and the collector plate welder (160) are arranged in multiples, the overall process efficiency of the collector plate welding device (100) can be increased.

[0226] For example, if the time it takes for the collector plate coupler (150) to couple the collector plate (30) to the electrode assembly (20) is at least twice as long as the center offset (CO) detection time in the offset detector (140), the tact time can be significantly reduced by arranging a plurality of collector plate couplers (150).

[0227] For example, the collector plate coupler (150) may include a first coupler (C1) and a second coupler (C2) that are arranged to be spaced apart along the transport direction (TD). The first coupler (C1) may include a positive coupler (CP1) and a negative coupler (CN1) that are arranged to face each other along the axial direction (z), and the second coupler (C2) may include a positive coupler (CP2) and a negative coupler (CN2) that are arranged to face each other along the axial direction (z).

[0228] Accordingly, the positive electrode collector plate (31) and the negative electrode collector plate (37) can be simultaneously joined to a pair of electrode assemblies (20), thereby increasing the overall efficiency of the collector plate welding device (100).

[0229] At this time, the offset transmission module (144) can transmit the center offset (CO) by dividing the electrode assembly (20) into units of transfer carriers (120). That is, the offset transmission module (144) is configured to store the center offset (CO) of the electrode assembly (20) in conjunction with the transfer carrier (120) on which the electrode assembly (20) is mounted, and transmit the center offset (CO) corresponding to the transfer carrier (120) positioned to face each collector plate coupler (150).

[0230] Accordingly, even when multiple collector plate couplers (150) are arranged, interference between the electrode assembly (20) and the center offset (CO) can be prevented in advance.

[0231] A plurality of collector plate welders (160) may be arranged to correspond to a plurality of collector plate couplers (150). In the present embodiment, a first welder (W1) and a second welder (W2) may be arranged to be spaced apart from each other along the transport direction (TD). The first welder (W1) may include a positive welder (WP1) and a negative welder (WN1) arranged to face each other along the axial direction (z), and the second welder (W2) may include a positive welder (WP2) and a negative welder (WN2) arranged to face each other along the axial direction (z).

[0232] Accordingly, the positive electrode collector plate (31) and the negative electrode collector plate (37) can be welded simultaneously for a pair of electrode assemblies (20), thereby increasing the overall efficiency of the collector plate welding device (100).

[0233] In addition, the number of collector plate welders (160) can be increased appropriately depending on the supply speed of the supply terminal (130). If the welding time of the collector plate welders (160) is longer than the supply time of the collector plate of the supply terminal (130), the number of collector plate welders (160) can be increased to shorten the overall process time of the welding device (100).

[0234] When the welding of the collector plate (30) and the electrode assembly (20) is completed, the joining jig (40) can be separated from the electrode assembly (20) to complete the electrode weldment (50), which is the electrode assembly (20) to which the collector plate (30) is welded. The transport carrier (120) on which the electrode weldment (50) is mounted can be transported to a discharge position to discharge the electrode weldment (50) to the outside of the collector plate welding device (100).

[0235] A discharge end (170) may be positioned adjacent to the discharge position of the transport track (110). For example, the discharge end (170) may be equipped with an extraction means such as a picker (not shown) to extract the electrode weldment (50) from the transport carrier (120) and load it on the outside of the transport track (110).

[0236] When the electrode weldment (50) is discharged by the discharge end (170), the empty transport carrier (120) without the electrode assembly (20) mounted thereon is transported back to the supply end (130) along the transport track (110) to accommodate a new electrode assembly (20).

[0237] A transport carrier (120) equipped with a new electrode assembly (20) passes through an offset detector (140), a collector plate coupler (150), and a collector plate welder (160) along a transport track (110) to form the electrode assembly (20) into an electrode welded body (50) and then discharge it to a discharge end (170). By repeating this process, a collector plate (30) can be automatically welded to the electrode assembly (20).

[0238] Although not shown, the transfer track (110), transfer carrier (120), supply end (130), offset detector (140), collector plate coupler (150), collector plate welder (160), and discharge end (170) can be organically controlled to automatically perform center alignment and welding of the electrode assembly (20) and collector plate (30). Accordingly, eccentricity defects of the electrode weld body (50) can be prevented.

[0239] For example, the control unit (180) can be electrically connected to the transfer track (110), the transfer carrier (120), the supply end (130), the offset detector (140), the collector plate coupler (150), the collector plate welder (160), and the discharge end (170).

[0240] In particular, the control unit (180) can communicate with the above-described components via wires or wirelessly. Although not shown, a predetermined sensor may be arranged in the transport track (110), transport carrier (120), supply end (130), offset detector (140), collector plate coupler (150), collector plate welder (160), and discharge end (170) to communicate with the control unit (180).

[0241] FIG. 19 is a flowchart illustrating a method of welding a collector plate to an electrode assembly using a collector plate welding device according to one embodiment of the present disclosure.

[0242] In the present disclosure, the current collector welding method (200) can be performed using the current collector welding device (100) illustrated in FIGS. 1 to 18. Accordingly, in the following, the same reference numerals are used for the same components as in FIGS. 1 to 18, and further detailed descriptions are omitted.

[0243] Referring to Fig. 19, in order to weld a collector plate (30) to an electrode assembly (20), a center offset (CO), which is a deviation between an electrode center position (ECP) of a cylindrical electrode assembly (20) extending along the axial direction (z) and a set reference position (RP), is first detected (step S11).

[0244] The cylindrical electrode assembly (20) may have a different geometric center depending on the deviation in mass and density distribution during the manufacturing process to have a jelly-roll configuration. Accordingly, the current collector welding method according to the present disclosure detects the actual center of the electrode assembly (20) being used in the welding process, which is the electrode center position (ECP), and then aligns the current collector center position (CCP), which is the center of the current collector plate (30) being welded, with the detected electrode center position (ECP), thereby preventing eccentricity defects of the electrode assembly (20) and the current collector plate (30).

[0245] A method for welding a collector plate according to one embodiment of the present disclosure can perform welding after aligning the centers of an electrode assembly (20) mounted on a transport carrier (120) moving along a transport track (110) and a collector plate (30) waiting for welding.

[0246] The transport track (110) is configured as a closed loop having a first position (Z1) where the electrode assembly (20) is supplied, a second position (Z2) where the center offset (CO) of the electrode assembly (20) to be welded is detected, a third position (Z3) where the collector plate (30) is temporarily attached to the electrode assembly (20), and a fourth position (Z4) where the collector plate (30) is permanently welded to the electrode assembly (20). A transport carrier (120) on which the electrode assembly (20) is mounted can be movably attached along the transport track (110).

[0247] Accordingly, the transport carrier (120) can form an electrode weldment (50) by welding the current collector (30) to the electrode assembly (20) while sequentially moving from the first position (Z1) to the fourth position (Z4) along the transport track (110) forming an infinite orbit.

[0248] The electrode assembly (20) to be welded can be supplied from the supply terminal (130) to the transport carrier (120) waiting at the first position (Z1), and the collector plate (30) to be welded can be supplied to the collector plate coupler (150) adjacent to the third position (Z3).

[0249] The electrode assembly (20) loaded onto the transport carrier (120) at the supply end (130) moves along the transport track (110) to a second position (Z2) to obtain information on the electrode center position (ECP), which is the actual center position of the electrode assembly (20), before the current collector welding is performed.

[0250] In this embodiment, the actual center position of the electrode assembly (20) can be confirmed by detecting the center offset (CO), which is the deviation from the reference position (RP) to the electrode center position (ECP).

[0251] The center offset (CO) can be detected by an offset detector (140) positioned opposite the electrode assembly (20) at the second position (Z2) of the transfer track (110). The offset detector (140) has substantially the same configuration as that disclosed in FIG. 8, and thus, a further detailed description thereof is omitted.

[0252] <01> FIG. 20 is a flowchart illustrating a center offset detection process illustrated in FIG. 19 according to one embodiment of the present disclosure.

[0253] <02> First, a surface profile (SP) regarding an end of the electrode assembly (20) is generated from a surface image of the electrode assembly (20) and displayed on a reference coordinate system (RC) having a reference position (RP) as an origin (step S111).

[0254] <03> A reference coordinate system (RC) having a set reference position (RP) as its origin can be displayed on a reference monitor (RM) of a vision inspector (141a), and a surface image captured through the vision inspector (141a) can be image-processed to generate a surface profile (SP).

[0255] <04> The reference monitor (RM) is positioned so that the reference position (RP), which is the center position of the sample assembly (SA), which is the sample electrode assembly (20), is located at the center, and the reference coordinate system (RC) is displayed so as to have the reference position (RP) as the origin, so that the surface profile (SP) displayed on the reference monitor (RM) can indicate the shape difference or center deviation of the electrode assembly (20) with respect to the sample assembly (SA).

[0256] <05> The surface profile (SP) is obtained from a surface image of an end of a cylindrical electrode assembly (20), and thus can be represented as a circle, which is a cross-section of the electrode assembly (20).

[0257] <06> Next, a virtual circle (VC) can be created that simultaneously connects three different points located on the outermost circumference of the surface profile (SP) displayed on the reference monitor (RM) (step S112).

[0258] <07> As shown in FIGS. 11 and 12, by randomly selecting three different points located on the outermost circumference of the surface profile (SP), a virtual circle (VC), which is a plane figure passing through the three points simultaneously, can be obtained using the built-in computer program using the three-point circle method.

[0259] <08> Since the only shape that passes through three different points simultaneously in the reference coordinate system (RC), which is a planar coordinate system, is a circle, a virtual circle (VC) can be easily obtained through a built-in algorithm.

[0260] <09> Next, the center of the virtual circle (VC) is obtained as the electrode center position (ECP), which is the coordinate in the reference coordinate system (RC) with respect to the actual center of the electrode assembly (20) located at the second position (Z2), and the coordinate of the electrode center position (ECP) can be detected as the center offset (CO) (step S113).

[0261] <10> Since the surface profile (SP) and the virtual circle (VC) of the end of the electrode assembly (20) are displayed on the reference coordinate system (RC), the center coordinates of the virtual circle (VC) can be obtained by calculation from the geometric characteristics of the virtual circle (VC).

[0262] <11> If the center coordinates of the virtual circle (VC) are the same as the origin of the reference coordinate system (RC), the actual center of the electrode assembly (20) is the same as the reference position (RP), and thus no center deviation occurs, there is no need to correct the center of the collector plate (30) to the center of the electrode assembly (20) at the third position (Z3).

[0263] <12> However, if the center coordinate of the virtual circle (VC) deviates from the origin of the reference coordinate system (RC), the actual center of the electrode assembly (20) deviates from the reference position (RP), resulting in a center deviation. In this case, it is required to correct the center of the collector plate (30) to the center of the electrode assembly (20) at the third position (Z3).

[0264] <13> At this time, the center coordinates of the obtained virtual circle (VC) are set to the electrode center position (ECP), which is the actual center of the electrode assembly (20), and the deviation between the reference position (RP) and the electrode center position (ECP) can be detected as a center offset (CO).

[0265] <14> In particular, in this embodiment, since the center coordinates of the virtual circle (VC) are obtained through calculation in the reference coordinate system (RC) with the reference position (RP) set as the origin, the center coordinates of the virtual circle (VC) itself, i.e., the coordinates of the electrode center position (ECP), can become the center offset (CO).

[0266] <15> Therefore, if the reference position (RP) is not the origin of the reference coordinate system (RC), the distance on the plane between the center position of the obtained virtual circle (VC) and the reference position (RP) can be detected as the center offset (CO).

[0267] <16> The reference position (RP) can be set to the center position of a virtual circle (VC) obtained by the three-point circle method as described above for the sample assembly (SA), which is the electrode assembly (20) selected as a sample before detecting the center offset (CO) for a specific electrode assembly (20).

[0268] <17> After detecting the reference position (RP) using the sample assembly (SA), as mentioned, the vision inspector (141a) can be positioned so that the reference position (RP) is located at the center of the reference monitor (RM), and a reference coordinate system (RC) having the reference position (RP) as the origin can be set.

[0269] <18> Thereafter, by detecting the center of a virtual circle (VC) displayed on a reference coordinate system (RC), the electrode center position (ECP) of each electrode assembly (20) and the center offset (CO) from the reference position (RP) can be obtained.

[0270] <19> When the center offset (CO) detection is completed at the second position (Z2), the transport carrier (120) on which the electrode assembly (20) is mounted can be transported to the third position (Z3). At the third position (Z3), the current collector (30) coupled to the current collector coupler (150) facing the electrode assembly (20) can be coupled to the end of the electrode assembly (20) so that the center positions are aligned with the electrode assembly (20).

[0271] <20> That is, the current collector plate (30) is positioned so that the current collector center position (CCP) is aligned with the initial position (IP) spaced apart from the reference position (RP) along the transfer direction (TD) of the electrode assembly (20), and is moved in parallel by the center offset (CO) so that the current collector plate (30) can be temporarily coupled to the electrode assembly (20) at the coupling position (CP) where the current collector center position (CCP) and the electrode center position (ECP) are aligned (step S12).

[0272] FIG. 21 is a flowchart showing a process of joining a current collector plate and an electrode assembly illustrated in FIG. 19 according to one embodiment of the present disclosure.

[0273] First, the collector plate (30) is coupled to the coupling load (151) whose load center axis (151s) is aligned with the initial position (IP) set at the third position (Z3) of the transfer track (110) so that the collector center position (CCP) is aligned with the load center axis (151s) (step S121).

[0274] At this time, the current collector plate (30) is fastened to one side of a coupling jig (40) having a circular disk shape corresponding to the end of the electrode assembly (20), and the coupling rod (151) can be detachably fastened to the other side of the coupling jig (40). Accordingly, the current collector plate (30) can be fastened to the coupling rod (151) via the coupling jig (40).

[0275] The collector plate coupler (150) is provided with a coupling rod (151), an alignment mount (152), and a load driver (153) and can be positioned to face the electrode assembly (20) at a third position (Z3). The collector plate (30) is coupled to the coupling rod (151) at the initial position (IP) to prepare for coupling the collector plate (30).

[0276] The initial position (IP) can be set simultaneously with the reference position (RP). The reference position (RP) is set to the center position of the sample assembly (SA) obtained by the three-point circle method, and the initial position (IP) is set at a position spaced apart from the reference position (RP) by a coupling gap, which is the gap between the second position (Z2) and the third position (Z3) along the transport direction (TD) of the transport carrier (120).

[0277] Therefore, the initial position (IP) may be the center position when the sample assembly (SA) is transferred to the third position (Z3).

[0278] The coupling load (151) is positioned so that the load center axis (151s) is aligned with the initial position (IP), and the collector plate (30) can be coupled to the coupling load (151) so that the collector center position (CCP) matches the load center axis (151s). Accordingly, the collector plate (30) can be coupled to the coupling load (151) so that the load center axis (151s) and the collector center position (CCP) match each other at the initial position (IP).

[0279] Next, the coupling rod (151) can be moved parallel by a center offset (CO) within an alignment plane perpendicular to the axial direction (z) of the electrode assembly (20) to align the rod center axis (151s) to the coupling position (CP) (step S122).

[0280] First, an aligned coordinate system (AC) is defined, which is a coordinate system that is a reference coordinate system (RC) that is translated along the transport direction (TD) by taking the initial position (IP) as the origin and extending it in the horizontal direction (HD) parallel to the transport direction (TD) and in the vertical direction (VD) perpendicular to the axial direction (z) and the horizontal direction (HD).

[0281] For example, the alignment monitor (AM) equipped on the alignment mount (152) is positioned so that the initial position (IP) is located at the center, and an alignment coordinate system (AC), which is a rectangular coordinate system with the initial position (IP) as the origin, is displayed by a built-in program. At this time, the alignment coordinate system (AC) may have two axes extending from the origin in the horizontal direction (HD) and the vertical direction (VD).

[0282] Therefore, the collector plate (30) whose center of current (CCP) is aligned with the initial position (IP) is positioned so that the origin of the alignment coordinate system (AC) and the center of current (CCP) coincide.

[0283] Next, the column driver (152b) can control the coupling load (151) to shift according to the center offset (CO) transmitted from the offset detector (140) so that the load center axis (151s) is aligned with the coupling position (CP).

[0284] For example, if the transmitted center offset (CO) is greater than the set tolerance, the first component and the second component can be extracted from the coordinates representing the center offset (CO) and transmitted to the horizontal drive unit (1521) and the vertical drive unit (1522), respectively.

[0285] The horizontal drive unit (1521) drives the alignment column (152a) to move the coupling rod (151) in parallel by a first component along the horizontal direction (HD) of the alignment coordinate system (AC), and the vertical drive unit (1522) drives the alignment column (152a) to move the coupling rod (151) in parallel by a second component along the vertical direction (VD) of the alignment coordinate system (AC).

[0286] Accordingly, the coupling load (151) moves from the origin of the alignment coordinate system (AC) by a center offset (CO) to the coupling position (CP), and the collector plate (30) coupled to be aligned with the load center axis (151s) of the coupling load (151) is also arranged to be aligned with the coupling position (CP).

[0287] That is, the current collector plate (30) can be arranged so that the current collector center position (CCP) and the coupling position (CP) are aligned with each other. The coupling position (CP) is a coordinate spaced apart by the center offset (CO) in the alignment coordinate system (AC), and represents the electrode center position (ECP) of the electrode assembly (20) located at the third position (Z3). Accordingly, the electrode assembly (20) arranged at the third position (Z3) can be located so that the center and the current collector plate (30) are on the same line along the axial direction (z) at the coupling position (CP).

[0288] When the shift to the coupling position (CP) of the coupling load (151) is completed, an alignment completion signal is generated and transmitted to the load driving unit (153), and according to the alignment completion signal, the load driving unit (153) moves the coupling load (151) along the axial direction (z) to press the jig assembly (40s) to which the current collector (30) is fastened to the end of the electrode assembly (20).

[0289] The jig assembly (40s) is temporarily fastened to the electrode assembly (20) so that the collector plate (30) is pressed against the end of the electrode assembly (20) by the jig body (B), and the coupling rod (151) is separated from the jig assembly (40s).

[0290] The separated coupling rod (151) returns to the initial position (IP) to prepare for coupling the collector plate (30) to the next electrode assembly (20).

[0291] The electrode assembly (20) to which the jig assembly (40s) is fastened is transported along the transport direction (TD) while being mounted on the transport carrier (120) to a fourth position (Z4). The collector plate welder (160) positioned at the fourth position can perform welding on the joint portion (34), which is a part of the collector plate (30) exposed through the welding opening (O) of the coupling jig (40), thereby permanently connecting the collector plate (30) to the electrode assembly (20).

[0292] When the welding of the collector plate (30) and the electrode assembly (20) is completed, the joining jig (40) can be separated from the collector plate (30) to form an electrode weldment (50). The electrode weldment (50) can be loaded onto a transport carrier (120) and transported to a discharge position.

[0293] At the discharge location, the electrode weldment (50) can be extracted from the transport carrier (120) by an extraction means such as a picker (not shown) and discharged to the outside of the welding device (100). The empty carrier (120a) separated from the electrode weldment (50) can continue to move along the transport track (110) and be recovered to the supply end (130).

[0294] The electrode assembly (20) to be welded can be re-mounted at the supply terminal (130) and the steps described above can be repeatedly performed using the offset detector (140), the collector plate coupler (150), and the collector plate welder (160). Accordingly, the electrode assembly (20) and the collector plate (30) are automatically welded to have a center offset (CO) lower than the allowable error, thereby significantly reducing step defects.

[0295] According to the current collector welding device (100) and the current collector welding method (200) using the same as described above, after detecting a unique electrode center position (ECP) for each electrode assembly (20) to be welded by an offset detector (140), the current collector center position (CCP), which is the center of the current collector (30), can be automatically aligned to the electrode center position (ECP) by a current collector coupler (150). Thereafter, by welding the current collector (30) to the electrode assembly (20) at a joining position (CP) where the electrode center position (ECP) and the current collector center position (CCP) are identical, the eccentricity defect of the electrode weldment (50) can be significantly reduced.

[0296] Accordingly, the yield of a secondary battery including an electrode weld (50) and a battery module or battery pack including the same can be increased and the operating stability can be improved.

[0297] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

[0298] The present disclosure can be used in the manufacture of energy storage devices and secondary batteries.

Claims

1. An offset detector for detecting a center offset, which is a deviation between the center position of an electrode of a cylindrical electrode assembly extending along an axis and a set reference position; A collector plate coupler that temporarily couples the collector plate to the electrode assembly at a coupling position where the collector center position is aligned with the electrode center position by moving the collector plate parallel to the center offset by the center offset along the transport direction of the electrode assembly from the reference position by the coupling gap; and A collector plate welding machine that permanently welds the temporarily joined collector plate to the electrode assembly. A collector plate welding device, including:

2. In the first paragraph, the offset detector, A profile generation module arranged to face the electrode assembly along the axial direction and generate a surface profile representing the shape of an end portion of the electrode assembly and displaying the surface profile on a reference coordinate system having the reference position as an origin; A shape generation module that extracts three different points located on the surface profile, creates a virtual circle connecting the three points simultaneously in the shape of the end, and detects the center of the virtual circle as the center position of the electrode; and An offset detection module that detects the coordinates of the center position of the electrode in the above reference coordinate system as the center offset. A collector plate welding device, including:

3. In paragraph 2, A current collector welding device, wherein the profile generation module includes a vision inspector having a reference monitor on which the reference coordinate system is displayed, and the virtual circle and the electrode center position are displayed on the reference monitor.

4. In paragraph 3, A current collector welding device, wherein the shape generation module and the offset detection module are implemented as a shape generation algorithm and a detection algorithm and are built into the offset detector.

5. In paragraph 2, A current collector welding device, wherein the reference position includes the center position of the virtual circle for a sample assembly, which is a sample electrode assembly having the same shape characteristics as the electrode assembly to be welded.

6. In the second paragraph, the collector plate coupler, A coupling rod that couples the collector plate to the end of the electrode assembly by pressing the collector plate along the axial direction at the coupling position so that the load center axis and the collector center position are aligned at the initial position; An alignment mount that is coupled to the coupling load to align the center axis of the load at the coupling position so as to move two-dimensionally in response to the center offset within an alignment plane perpendicular to the axial direction; and A load driving unit that moves the coupling load, with the load center axis aligned at the coupling position, along the axial direction to press the current collector plate against the electrode assembly. A collector plate welding device, including:

7. In the 6th paragraph, the collector plate coupler, The electrode assembly has a circular disk shape corresponding to the end of the electrode assembly, the collector plate is fastened to one side, and the coupling rod is connected to the other side symmetrical to the one side. A coupling jig that is detachably connected to the electrode assembly by transferring the coupling rod and couples the current collector to the electrode assembly. A welding device for a collector plate, further comprising:

8. In paragraph 7, A current collector plate welding device, wherein the above-mentioned joining jig is configured to have a plurality of welding openings symmetrically arranged from the center of the disk, so as to weld a joint portion, which is a part of the current collector plate exposed through the welding opening, and an end portion of the electrode assembly.

9. In paragraph 8, A collector plate welding device, wherein the collector plate welding device is configured to apply one of ultrasonic waves and laser through the welding opening.

10. In the 6th paragraph, the alignment mount, An alignment column capable of transporting the coupling load along a horizontal direction parallel to the transport direction and a vertical direction perpendicular to the axial direction and the horizontal direction, respectively; An alignment monitor that displays an alignment coordinate system that is a coordinate system that has the initial position as the origin and is extended in the horizontal and vertical directions to move the reference coordinate system in parallel along the transfer direction; and A column driver that moves the alignment column along the center offset based on the alignment coordinate system and aligns the load center axis aligned at the initial position to the joining position. A collector plate welding device, including:

11. In the 10th paragraph, the column driver, A horizontal driving unit that horizontally drives the alignment column so that the load center axis moves from an initial position that is the center of the alignment coordinate system to a first driving position spaced apart by a first component of the center offset along the horizontal direction; and Including a vertical drive unit that vertically drives the alignment column so that the load center axis moves from an initial position that is the center of the alignment coordinate system to a second drive position spaced apart by a second component of the center offset along the vertical direction, A current collector welding device, wherein the above-mentioned joining position is determined by the coordinates of the alignment coordinate system having the first driving position and the second driving position.

12. In the 11th paragraph, the column driver, After the above electrode assembly and the above collector plate are combined, A collector plate welding device further comprising a load return unit that releases the connection between the collector plate and the coupling rod and returns the coupling rod to the initial position so that the center axis of the load and the initial position are aligned.

13. In paragraph 12, A collector plate welding device, wherein the load return unit controls the horizontal drive unit and the vertical drive unit, respectively, so that the alignment column moves in the reverse horizontal direction and the reverse vertical direction by the first component and the second component, respectively.

14. In the 10th paragraph, the column driver, A current collector welding device comprising an error comparison unit that compares the center offset with a stored tolerance and controls the alignment column to be driven only when the center offset is greater than the tolerance.

15. In the 10th paragraph, the column driver, An alignment signal generating unit that generates an alignment completion signal when the above load center axis is aligned with either the above coupling position or the above initial position. A welding device for a collector plate, further comprising:

16. In paragraph 1, Further comprising at least one transport carrier movably coupled to a transport track provided as an infinite track, circulating along the transport track along the transport direction and carrying the electrode assembly; A collector plate welding device, wherein the offset detector, the collector plate coupler, and the collector plate welder are sequentially arranged along the conveying direction at a position adjacent to the conveying track.

17. A step of detecting a center offset, which is a deviation between the electrode center position of a cylindrical electrode assembly extending along the axis direction and a set reference position; A step of temporarily joining the collector plate to the electrode assembly at a joining position where the collector center position and the electrode center position are aligned by moving the collector plate parallel to the center offset from the reference position to the initial position spaced apart from the reference position along the transport direction of the electrode assembly; and A step of permanently bonding the temporarily bonded collector plate to the electrode assembly by welding the temporarily bonded collector plate to the electrode assembly. A method for welding a current collector plate, comprising:

18. In the 17th paragraph, the step of detecting the center offset comprises: A step of generating a surface profile of an end portion of the electrode assembly from a surface image of the electrode assembly and displaying the surface profile on a reference coordinate system having the reference position as an origin; A step of generating a virtual circle that simultaneously connects three different points located on the outermost circumference of the surface profile; and A step of obtaining the center of the virtual circle as the electrode center position and detecting the coordinates of the electrode center position in the reference coordinate system as the center offset. A method for welding a current collector plate, comprising:

19. In the 18th paragraph, the step of combining the current collector plate to the electrode assembly is: A step of coupling the collector plate to the coupling load so that the load center axis and the collector center position are aligned at the initial position; A step of aligning the center axis of the load at the coupling position by moving the coupling load in parallel by the center offset within the alignment plane perpendicular to the axial direction; and A step of moving the coupling rod along the axial direction at the coupling position to fasten the current collector to the end of the electrode assembly. A method for welding a current collector plate, comprising:

20. In the 19th paragraph, the step of aligning the load center axis to the coupling position is: A step of defining an alignment coordinate system, which is a coordinate system that is a coordinate system that is moved in parallel along the transport direction by taking the initial position as the origin and extending in a horizontal direction parallel to the transport direction and in a vertical direction perpendicular to the axial direction and the horizontal direction; a step of moving the coupling load along the horizontal direction by a first component constituting the coordinates of the center offset from the initial position; and A step of moving the above-mentioned coupling load along the vertical direction by a second component constituting the coordinates of the center offset from the above-mentioned initial position. A method for welding a current collector plate, comprising:

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