Clamping jig for laser welding

Abstract

The present invention relates to a pressure jig for laser welding for applying pressure to a busbar when laser welding the positive and negative portions of a busbar disposed on a battery cell stack to the positive and negative portions of the battery cell, respectively. The jig comprises: a jig body spaced apart from the upper portion of the busbar, configured to be movable in a vertical direction, and having a laser hole formed to allow a laser to pass through; a linear guide mounted on the jig body and having a shaft configured to be movable in an axial direction; a pressure block coupled to the end of the shaft and configured to apply pressure to the busbar by the movement of the jig body, and having a welding hole that guides the laser passing through the laser hole to the welding position of the positive portion and the negative portion in the applied pressure state; and a plurality of magnet members spaced apart such that the same poles face each other along the axial direction of the shaft while being fitted onto the shaft. When the pressure block applies pressure to the busbar, the shaft moves toward the jig body, thereby reducing the distance between the plurality of magnet members, and due to the reduction in the distance, the plurality of magnets It is characterized by an increase in the magnetic repulsion acting between each member.

Description

Technology Field

[0001] The present invention relates to a pressure jig for laser welding, and more specifically, to a pressure jig for laser welding for applying pressure to a busbar when laser welding the positive and negative portions of a busbar disposed on a battery cell stack to the positive and negative portions of the battery cell, respectively. Background Technology

[0002] In the manufacturing process of a battery module or battery pack, a plurality of battery cells are stacked to form a battery cell stack, and electrical connection between battery cells can be achieved by bonding the positive and negative portions of a busbar disposed on the battery cell stack to the positive and negative portions of the battery cells.

[0003] Laser welding can be applied to the joining process of these busbars, and to ensure laser welding quality, it is necessary to reduce the gap between the busbar and the battery cell and maintain a stable, tight contact between the busbar and the welding location. To this end, a laser welding pressure jig can be used to apply pressure to the busbar towards the battery cell during laser welding.

[0004] However, battery cell stacks may include cell stacking tolerances, cell height deviations, bending of busbars, or assembly errors, and if the heights of different parts of the battery cells differ, the pressure conditions required for each area of ​​the busbar may also differ. When the busbar is pressured under such conditions, excessive pressure may be applied to some areas while sufficient pressure may not be transmitted to other areas.

[0005] In addition, if the pressure is applied excessively or unevenly, there is a risk of deformation of the busbar or battery cell, misalignment of the welding position, welding defects, and reduced reliability of the electrical connection.

[0006] Accordingly, there is a need to develop a pressure jig for laser welding that can stably apply pressure to the busbar while reducing excessive application or fluctuation of pressure when laser welding battery cells and busbars. The problem to be solved

[0007] One objective of the present invention is to provide a pressure jig for laser welding that can stably apply pressure to the busbar while reducing excessive application or uneven transmission of pressure when laser welding the positive and negative portions of the busbar disposed on the battery cell stack to the positive and negative portions of the battery cell, respectively.

[0008] Another objective of the present invention is to provide a laser welding system capable of improving the laser welding quality and electrical connection reliability of a busbar and a battery cell.

[0009] Another objective of the present invention is to provide a laser welding method capable of laser welding a positive electrode and a negative electrode to the positive and negative electrodes of a battery cell, respectively, while stably pressurizing a busbar. means of solving the problem

[0010] To achieve the above-mentioned objectives, a pressure jig for laser welding according to a first embodiment of the present invention comprises a plurality of magnetic members spaced apart such that their identical poles face each other along the axial direction while fitted onto a shaft, and when a pressure block presses a bus bar, the shaft moves toward the jig body, thereby reducing the distance between the plurality of magnetic members, and the magnetic repulsion force acting between each of the plurality of magnetic members increases due to the reduction in the distance between them.

[0011] More specifically, a pressure jig for laser welding according to a first embodiment of the present invention is a pressure jig for laser welding for applying pressure to a bus bar when laser welding a positive and negative portion of a bus bar disposed on a battery cell stack to the positive and negative portions of the battery cell, respectively, and comprises: a jig body spaced apart above the bus bar, configured to be movable in a vertical direction, and having a laser hole formed to allow a laser to pass through; a linear guide mounted on the jig body and having a shaft configured to be movable in an axial direction; a pressure block coupled to the end of the shaft and configured to apply pressure to the bus bar by the movement of the jig body, and having a welding hole that guides the laser passing through the laser hole in the applied state to the welding position of the positive portion and the negative portion; and a plurality of magnet members spaced apart so that the same poles face each other along the axial direction of the shaft while fitted onto the shaft, wherein when the pressure block applies pressure to the bus bar, the shaft moves toward the jig body, thereby reducing the distance between the plurality of magnet members, and It is characterized by an increase in the magnetic repulsion force acting between each of the plurality of magnetic members due to a decrease in the separation distance.

[0012] According to one example related to the present invention, when the pressure block presses the bus bar, the shaft is pressed by the reaction force transmitted from the bus bar and moves toward the jig body, and as the distance between the plurality of magnetic members decreases due to the movement of the shaft, the magnetic repulsion force increases, so that the pressure applied to the bus bar can be buffered.

[0013] According to one example related to the present invention, at least one of the plurality of magnetic members is formed to be slidable along the axial direction while fitted onto the outer surface of the shaft, and as the shaft moves, at least one of the plurality of magnetic members slides toward another adjacent one of the plurality of magnetic members, thereby reducing the distance between the plurality of magnetic members.

[0014] According to one example related to the present invention, the plurality of magnet members may include a first magnet member disposed at one end of the shaft, a second magnet member disposed at the other end of the shaft and supported by one surface of the pressure block, and at least one intermediate magnet member disposed between the first magnet member and the second magnet member in a floating state due to the magnetic repulsion force and configured to slide along the axial direction.

[0015] According to one example related to the present invention, the jig body comprises a base portion having a first laser hole that is movably formed on the bus bar and forms at least a part of the laser hole, and a pivot portion having a second laser hole that is rotatably coupled to the base portion and communicates with the first laser hole and forms at least another part of the laser hole, and the linear guide is mounted on the pivot portion so that the direction of the pressure block can be aligned to correspond to the arrangement direction of the bus bar by the relative rotation.

[0016] According to one example related to the present invention, the jig body may further include a power transmission unit coupled to the base portion and transmitting a driving force required for relative rotation, and a power receiving unit disposed between the base portion and the rotating portion and receiving a driving force from the power transmission unit to rotate the rotating portion.

[0017] According to one example related to the present invention, the power transmission unit may comprise a motor bracket coupled to the base portion, a rotary motor mounted on the motor bracket and spaced laterally from the rotating portion, and a timing belt connecting the rotary motor and the power receiving unit to transmit the driving force generated by the rotary motor to the power receiving unit.

[0018] According to one example related to the present invention, the pressure block comprises a first pressure block and a second pressure block that respectively apply pressure to the anode and the cathode by the movement of the jig body, and the welding hole comprises a first welding hole and a second welding hole formed through the first pressure block and the second pressure block, respectively, and the first pressure block and the second pressure block may be formed to be interlockable with each other.

[0019] According to one example related to the present invention, the first welding hole is configured to guide a laser passing through the laser hole to a welding position of the anode while the first pressure block is pressing the anode, and the second welding hole is configured to guide a laser passing through the laser hole to a welding position of the cathode while the second pressure block is pressing the cathode, and in the interlocking state, the perimeter of the second welding hole may be arranged to surround at least a portion of the perimeter of the first welding hole.

[0020] According to one example related to the present invention, the lower surface of the first pressure block may be provided with a first pressure projection formed protruding from the perimeter of the first welding hole to press the anode portion by the movement of the jig body, and the lower surface of the second pressure block may be provided with a second pressure projection formed protruding from the perimeter of the second welding hole to press the cathode portion by the movement of the jig body.

[0021] According to one example related to the present invention, when the positive electrode and the negative electrode of the battery cell are formed at different heights, the positive electrode portion and the negative electrode portion are arranged to cover the positive electrode and the negative electrode, respectively, to form a predetermined height step, and the first pressure block and the second pressure block may be formed to be mutually separable so as to be able to press the positive electrode portion and the negative electrode portion, respectively, in correspondence with the height step.

[0022] According to one example related to the present invention, the linear guide comprises a first linear guide and a second linear guide spaced apart from each other with the laser hole in between, and the first and second pressure blocks may be respectively coupled to the ends of the shafts provided in each of the first and second linear guides.

[0023] According to one example related to the present invention, when the first pressure block and the second pressure block each apply pressure to the positive electrode and the negative electrode, the spacing distance between the plurality of magnetic members fitted onto the shaft provided in the first linear guide and the spacing distance between the plurality of magnetic members fitted onto the shaft provided in the second linear guide may be formed differently from each other.

[0024] Meanwhile, a laser welding system according to the first embodiment of the present invention is characterized by comprising a laser welding pressure jig described above and a laser scanner that irradiates a laser to sequentially pass through the laser hole and the welding hole when the laser welding pressure jig presses the bus bar, thereby laser welding the anode and the cathode to the anode and the cathode, respectively.

[0025] In addition, a laser welding method using the laser welding system according to the first embodiment of the present invention comprises: (a) a step of placing the laser welding pressure jig on the busbar; (b) a step of contacting the pressure block with the busbar; and (c) a step of laser welding the anode and the cathode to the anode and the cathode, respectively, using the laser scanner while applying pressure to the busbar with the pressure block; wherein, in step (c), when the pressure block applies pressure to the busbar, the shaft moves toward the jig body so that the distance between the plurality of magnetic members decreases, and the magnetic repulsion force acting between each of the plurality of magnetic members increases due to the decrease in the distance between them.

[0026] To achieve the above-mentioned objectives, a pressure jig for laser welding according to a second embodiment of the present invention comprises a sensing unit installed in at least one of a jig body and a linear driving unit to detect a pressure applied to a bus bar, and is characterized in that, based on the detection result of the sensing unit, the movement of a moving rod is feedback-controlled so that the pressure applied to the bus bar is maintained at a preset target pressure.

[0027] More specifically, a pressure jig for laser welding according to a second embodiment of the present invention is a pressure jig for laser welding for applying pressure to a bus bar when laser welding a positive and negative portion of a bus bar disposed on a battery cell stack to the positive and negative portions of the battery cell, respectively, and comprises: a jig body spaced apart from the upper portion of the bus bar and having a laser hole formed to allow a laser to pass through; a linear driving unit mounted on the jig body and having a moving rod formed to be movable in an axial direction; a pressure block coupled to the end of the moving rod and configured to apply pressure to the bus bar by the movement of the moving rod, and having a welding hole that guides the laser passing through the laser hole to the welding position of the positive and negative portions in the pressured state; and a sensing unit installed in at least one of the jig body and the linear driving unit to detect a pressure applied to the bus bar, wherein the movement of the moving rod is feedback controlled based on the detection result of the sensing unit so that the pressure applied to the bus bar is maintained at a preset target pressure.

[0028] According to one example related to the present invention, the movement of the moving rod is achieved by supplying a driving medium to the linear driving unit, and based on the detection result of the sensing unit, the supply of the driving medium is adjusted in real time so that the movement of the moving rod can be feedback controlled.

[0029] According to one example related to the present invention, based on the detection result of the sensing unit, when the pressure applied to the busbar reaches the preset target pressure, the supply of the driving medium can be finely adjusted so as to maintain the target pressure.

[0030] According to one example related to the present invention, based on the difference between the detection result of the sensing unit and the preset target pressure, the supply, blocking, and supply amount of the driving medium are adjusted so that the amount of movement of the moving rod can be controlled.

[0031] According to one example related to the present invention, the jig body comprises a base portion having a first laser hole that is movably formed on the bus bar and forms at least a part of the laser hole, and a pivot portion having a second laser hole that is rotatably coupled to the base portion and communicates with the first laser hole and forms at least another part of the laser hole, and the linear driving unit is mounted on the pivot portion so that the direction of the pressure block can be aligned to correspond to the arrangement direction of the bus bar by the relative rotation.

[0032] According to one example related to the present invention, the jig body may further include a power transmission unit coupled to the base portion and transmitting a driving force required for relative rotation, and a power receiving unit disposed between the base portion and the rotating portion and receiving a driving force from the power transmission unit to rotate the rotating portion.

[0033] According to one example related to the present invention, the power transmission unit may comprise a motor bracket coupled to the base portion, a rotary motor mounted on the motor bracket and spaced laterally from the rotating portion, and a timing belt connecting the rotary motor and the power receiving unit to transmit the driving force generated by the rotary motor to the power receiving unit.

[0034] According to one example related to the present invention, the pressure block comprises a first pressure block and a second pressure block that respectively apply pressure to the anode and the cathode by the movement of the moving rod, and the welding hole comprises a first welding hole and a second welding hole formed through the first pressure block and the second pressure block, respectively, and the first pressure block and the second pressure block may be formed to be interlockable with each other.

[0035] According to one example related to the present invention, the first welding hole is configured to guide a laser passing through the laser hole to a welding position of the anode while the first pressure block is pressing the anode, and the second welding hole is configured to guide a laser passing through the laser hole to a welding position of the cathode while the second pressure block is pressing the cathode, and in the interlocking state, the perimeter of the second welding hole may be arranged to surround at least a portion of the perimeter of the first welding hole.

[0036] According to one example related to the present invention, when the positive electrode and the negative electrode of the battery cell are formed at different heights, the positive electrode portion and the negative electrode portion are arranged to cover the positive electrode and the negative electrode, respectively, to form a predetermined height step, and the first pressure block and the second pressure block may be formed to be mutually separable so as to be able to press the positive electrode portion and the negative electrode portion, respectively, in correspondence with the height step.

[0037] According to one example related to the present invention, the linear driving unit comprises a first linear driving unit and a second linear driving unit spaced apart from each other with the laser hole in between, and the first and second pressure blocks may be respectively coupled to the ends of the moving rods provided in each of the first and second linear driving units.

[0038] According to one example related to the present invention, the sensing unit includes a first sensing unit and a second sensing unit that detect pressure applied to each of the anode and the cathode, and based on the detection results of each of the first and second sensing units, the movement of the moving rods provided in each of the first and second linear driving units can be individually feedback controlled.

[0039] Meanwhile, a laser welding system according to a second embodiment of the present invention is characterized by comprising: a pressure jig for laser welding described above; a laser scanner that irradiates a laser to sequentially pass through the laser hole and the welding hole when the pressure jig for laser welding presses the bus bar, thereby laser welding the anode and the cathode to the anode and the cathode, respectively; and a control unit that feedback controls the movement of the moving rod based on the detection result of the sensing unit.

[0040] According to one example related to the present invention, the system further includes a regulator that regulates the supply of a driving medium supplied to the linear driving unit, and the control unit may be configured to control the operation of the regulator to provide feedback control of the movement of the moving rod.

[0041] In addition, a laser welding method using the laser welding system according to the second embodiment of the present invention comprises: (a) a step of placing the laser welding pressure jig on the busbar; (b) a step of contacting the pressure block with the busbar; and (c) a step of laser welding the anode and the cathode to the anode and the cathode, respectively, using the laser scanner while applying pressure to the busbar with the pressure block, wherein in step (c), the control unit feedback-controls the movement of the moving rod based on the detection result of the sensing unit. Effects of the invention

[0042] The effect obtained through the solution means according to the first embodiment of the present invention described above is as follows.

[0043] First, the pressure jig for laser welding according to the first embodiment of the present invention has a plurality of magnetic members fitted onto a shaft and spaced apart so that their identical poles face each other along the axial direction. When the pressure block presses the bus bar, the shaft moves toward the jig body, and as the distance between the plurality of magnetic members decreases, the magnetic repulsion force increases non-linearly. Consequently, the pressure is buffered in a non-contact manner, thereby reducing the need for parts replacement due to wear or deformation of the buffering means, while allowing the bus bar to be pressed stably and reducing excessive application or uneven transmission of the pressure.

[0044] Second, the laser welding system according to the first embodiment of the present invention can laser weld the positive and negative portions to the positive and negative portions of the battery cell, respectively, by irradiating a laser so that a laser scanner sequentially passes through a laser hole and a welding hole while a pressure jig for laser welding presses the busbar, thereby having the effect of improving the laser welding quality and electrical connection reliability of the busbar and the battery cell.

[0045] Third, the laser welding method according to the first embodiment of the present invention has the effect of providing an efficient laser welding method that allows the positive and negative portions to be laser welded to the positive and negative portions of a battery cell, respectively, while stably pressing the busbar, without the need for a separate pressure adjustment process due to cell stacking tolerances or height deviations of the busbar, because the magnetic repulsion force between a plurality of magnetic members fitted to the shaft during the process in which the pressure block presses the busbar buffers the pressure force in a non-contact manner.

[0046] The effect obtained through the solution means according to the second embodiment of the present invention described above is as follows.

[0047] First, the pressure jig for laser welding according to the second embodiment of the present invention has the effect of stably applying pressure to the bus bar without using elastic members such as springs, while reducing excessive application or uneven transmission of pressure, because a sensing unit installed in at least one of the jig body and the linear driving unit detects the pressure applied to the bus bar, and the movement of the moving rod is feedback controlled based on the detection result of the sensing unit so that the pressure is maintained at a preset target pressure.

[0048] Second, the laser welding system according to the second embodiment of the present invention has the effect of improving the laser welding quality and electrical connection reliability of the busbar and the battery cell, as the laser scanner irradiates a laser to sequentially pass through a laser hole and a welding hole while the control unit controls the supply of a driving medium in real time based on the detection result of a sensing unit to feedback control the movement of a moving rod, thereby enabling laser welding of the positive and negative parts to the positive and negative parts of the battery cell, respectively.

[0049] Third, the laser welding method according to the second embodiment of the present invention has the effect of providing an efficient laser welding method that can laser weld the positive and negative parts to the positive and negative parts of a battery cell, respectively, while stably pressing the busbar, because the control unit feedback controls the movement of the moving rod based on the detection result of the sensing unit to maintain the pressure at a preset target pressure. Brief explanation of the drawing

[0050] FIG. 1 is a perspective view illustrating a busbar placed on a battery cell stack. FIG. 2 is an overall configuration diagram of a pressure jig for laser welding according to a first embodiment of the present invention. Figure 3 is an example of the operation of the pressure jig for laser welding of Figure 2. FIG. 4 is a conceptual diagram showing the first magnet member, the second magnet member, and the intermediate magnet member fitted onto the shaft of FIG. 2. Figure 5 is a cross-sectional view AA' of the laser welding pressure jig of Figure 2. Figure 6 is an upper view of the pressure jig for laser welding of Figure 2. FIG. 7 is an overall configuration diagram of a pressure jig for laser welding according to a second embodiment of the present invention. Figure 8 is an example of the operation of the pressure jig for laser welding of Figure 7. Figure 9 is a cross-sectional view of BB' of the laser welding pressure jig of Figure 7. Figure 10 (a) is a perspective view showing the upper structure of the pressure block, and (b) is a perspective view showing the lower structure of the pressure block. Figure 11 is a conceptual diagram showing the pressure block of Figure 10 applying pressure to the bus bar. FIG. 12 is a block diagram showing the configuration of a laser welding system according to a first embodiment and a second embodiment. FIG. 13 is a block diagram showing feedback control of a control unit according to a second embodiment. Specific details for implementing the invention

[0051] Hereinafter, a pressure jig (100, 200) for laser welding according to the first and second embodiments of the present invention will be described in more detail with reference to the drawings.

[0052] In describing the embodiments disclosed in this specification, if it is determined that a detailed description of related prior art could obscure the essence of the embodiments disclosed in this specification, such detailed description is omitted.

[0053] The attached drawings are intended only to facilitate understanding of the embodiments disclosed in this specification, and the technical concept disclosed in this specification is not limited by the attached drawings; it should be understood that all modifications, equivalents, and substitutions included within the concept and technical scope of the present invention are included.

[0054] In this specification, similar or identical reference numbers are assigned to identical components even in different embodiments, and redundant descriptions thereof are omitted.

[0055] A singular expression includes a plural expression unless the context clearly indicates otherwise.

[0056] In this application, terms such as "comprising" or "having" are intended to indicate the existence of the features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, and should be understood as not excluding in advance the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof.

[0057] FIG. 1 is a perspective view of a bus bar (2) placed on a stack of battery cells (1).

[0058] Referring to FIG. 1 below, a battery cell (1) stack may be formed by stacking or arranging a plurality of battery cells (1), and a bus bar (2) may be placed on the battery cell (1) stack to electrically connect the plurality of battery cells (1).

[0059] Specifically, the positive electrode (11) of the battery cell (1) may be formed at the center of the battery cell (1), and the negative electrode (12) of the battery cell (1) may be formed at the shoulder of the battery cell (1). Here, the shoulder may be located at the top of the battery cell (1) and outside the center, and may be a portion forming the perimeter area at the end of the battery cell (1).

[0060] The busbar (2) may include an anode portion (21) positioned to cover the anode (11) and a cathode portion (22) positioned to cover the cathode (12). The anode portion (21) may be laser welded to the anode (11) of the battery cell (1), and the cathode portion (22) may be laser welded to the cathode (12) of the battery cell (1).

[0061] At this time, if the contact between the busbar (2) and the battery cell (1) is unstable or the busbar (2) is lifted away from the welding position, the quality of the laser welding may be degraded. Therefore, when laser welding the positive portion (21) and the negative portion (22) of the busbar (2) to the positive (11) and negative (12) of the battery cell (1), respectively, it is necessary to stably press the busbar (2) toward the battery cell (1) stack side.

[0062] Hereinafter, a first embodiment and a second embodiment of the laser welding pressure jig (100, 200) of the present invention for solving the above-described technical problem will be explained with reference to the drawings.

[0063] FIG. 2 is an overall configuration diagram of a pressure jig (100) for laser welding according to a first embodiment of the present invention. FIG. 3 is an example diagram of the operation of the pressure jig (100) for laser welding of FIG. 2. FIG. 4 is a conceptual diagram showing a first magnet member (141), a second magnet member (142), and an intermediate magnet member (143) fitted onto the shaft (120a1, 120b1) of FIG. 2.

[0064] Hereinafter, with reference to FIGS. 2 to 4, the overall configuration of a pressure jig (100) for laser welding according to the first embodiment of the present invention will be described.

[0065] It is preferable that the pressure jig (100) for laser welding be configured to stably maintain the contact state between the bus bar (2) and the battery cell (1), while preventing deformation of the bus bar (2) or the battery cell (1) due to excessive pressure.

[0066] In this case, if a contact-type cushioning means, such as an elastic member like a spring, is to be used as a cushioning means for the applied pressure, material fatigue or wear of the elastic member may occur due to repetitive pressing motions, and consequently, the cushioning characteristics of the elastic member may change over time, making it difficult to maintain constant pressing conditions.

[0067] To this end, the laser welding pressure jig (100) according to the present embodiment includes a jig body (110), a linear guide (120), a pressure block (130), and a plurality of magnetic members (140).

[0068] The jig body (110) is spaced apart from the upper part of the bus bar (2), is configured to be movable in a vertical direction, and has a laser hole (111) formed to allow a laser to pass through.

[0069] The linear guide (120) is mounted on the jig body (110) and has a shaft (120a1, 120b1) formed to be movable in the axial direction.

[0070] For example, the linear guide (120) is provided with a guide housing (120a2, 120b2) that accommodates at least a portion of a shaft (120a1, 120b1) inside, and the shaft (120a1, 120b1) may be formed to be movable relative to the guide housing (120a2, 120b2) along the axial direction.

[0071] More specifically, a guide bush may be provided inside the guide housing (120a2, 120b2), and the shaft (120a1, 120b1) may be guided to move along the axial direction by the guide bush.

[0072] The pressure block (130) is coupled to the end of the shaft (120a1, 120b1) and is configured to press the bus bar (2) by the movement of the jig body (110), and has a welding hole (130a1, 130b1) that guides the laser passing through the laser hole (111) in the pressure state to the welding position of the positive part (21) and the negative part (22).

[0073] A plurality of magnetic members (140) are spaced apart so that their identical poles face each other along the axial direction of the shaft (120a1, 120b1) while being fitted onto the shaft (120a1, 120b1).

[0074] For example, one of the plurality of magnetic members (140) may be positioned such that the N pole is located on the upper side and the S pole is located on the lower side, and another of the plurality of magnetic members (140) positioned on the lower side of said one may be positioned such that the S pole is located on the upper side and the N pole is located on the lower side.

[0075] As shown in FIGS. 2 and 3, a plurality of magnetic members (140) may be provided in at least two, and as shown in FIG. 4, they may be provided in three or more corresponding to the length of the shaft (120a1, 120b1). Meanwhile, in FIGS. 3 and 4, some configurations have been omitted or simplified for convenience of explanation.

[0076] Additionally, when the pressure block (130) presses the bus bar (2), the shaft (120a1, 120b1) moves toward the jig body (110), reducing the distance between the plurality of magnetic members (140), and due to the reduction in the distance, the magnetic repulsion force acting between each of the plurality of magnetic members (140) increases.

[0077] Accordingly, the laser welding pressure jig (100) according to the present embodiment can buffer the pressure applied to the bus bar (2) by utilizing the magnetic repulsion force acting between a plurality of magnetic members (140).

[0078] In particular, the magnetic repulsion force acting between multiple magnetic members (140) increases non-linearly as the distance between them decreases, so it has a self-balancing characteristic in which the cushioning effect increases as the pressure increases.

[0079] In addition, since the multiple magnetic members (140) are non-contact cushioning means that do not physically contact each other, unlike elastic members such as springs, material fatigue and wear caused by repetitive pressure movements do not occur, so the cushioning characteristics are maintained over time.

[0080] Below, the pressure buffering mechanism by the plurality of magnetic members (140) described above will be explained in more detail.

[0081] When the pressure block (130) presses the bus bar (2), the shaft (120a1, 120b1) can be pressed by the reaction force transmitted from the bus bar (2) and moved toward the jig body (110).

[0082] In addition, as the distance between the plurality of magnetic members (140) decreases due to the movement of the shaft (120a1, 120b1), the magnetic repulsion force increases, so that the pressure applied to the bus bar (2) can be buffered.

[0083] More specifically, as the distance between the plurality of magnetic members (140) fitted onto the shaft (120a1, 120b1) decreases, the magnetic repulsion force increases non-linearly, thereby preventing excessive pressure from being applied to the bus bar (2).

[0084] Meanwhile, a plurality of magnetic members (140) are formed in an annular shape so as to be fitted onto the outer surface of a shaft (120a1, 120b1), and at least one of the plurality of magnetic members (140) may be formed to be slidable along the axial direction while fitted onto the outer surface of the shaft (120a1, 120b1).

[0085] Here, the sliding may mean that a plurality of magnetic members (140) move relative to the shaft (120a1, 120b1) along the axial direction on the outer surface of the shaft (120a1, 120b1).

[0086] Additionally, by moving the shaft (120a1, 120b1), at least one of the plurality of magnetic members (140) can be slid toward another adjacent one of the plurality of magnetic members (140), thereby reducing the distance between the plurality of magnetic members (140).

[0087] For example, the inner diameter of at least one of the plurality of magnetic members (140) is formed to be larger than the outer diameter of the shaft (120a1, 120b1), so that a radial gap may be formed between the inner diameter and the outer surface of the shaft (120a1, 120b1).

[0088] A plurality of magnetic members (140) may include a first magnetic member (141), a second magnetic member (142), and at least one intermediate magnetic member (143).

[0089] The first magnetic member (141) may be positioned on one end of the shaft (120a1, 120b1). For example, the first magnetic member (141) may be positioned to be fixed to the guide housing (120a2, 120b2) on one end of the shaft (120a1, 120b1) while being fitted onto the outer circumference of the shaft (120a1, 120b1).

[0090] Here, the end side of the shaft (120a1, 120b1) may mean a position relatively adjacent to the end of the shaft (120a1, 120b1) than the position where the second magnet member (142) and the intermediate magnet member (143) are arranged along the axial direction of the shaft (120a1, 120b1).

[0091] For example, one of the N pole and S pole of the first magnetic member (141) may be supported and fixed inside the guide housing (120a2, 120b2), and the other of the N pole and S pole may be positioned to protrude outside the guide housing (120a2, 120b2).

[0092] The second magnetic member (142) is positioned at the other end of the shaft (120a1, 120b1) and can be supported by one side of the pressure block (130). Additionally, the second magnetic member (142) can be configured to move relative to the first magnetic member (141) by the movement of the jig body (110) while being supported by one side of the pressure block (130).

[0093] The intermediate magnet member (143) is positioned so as to be floating due to magnetic repulsion between the first magnet member (141) and the second magnet member (142), and can be slidable along the axial direction.

[0094] Accordingly, the intermediate magnet member (143) can slide freely in the axial direction without physically contacting the shaft (120a1, 120b1) or the first magnet member (141) and the second magnet member (142), so that variations in cushioning characteristics due to friction can be minimized.

[0095] According to the detailed configuration of the multiple magnet members (140) described above, an intermediate magnet member (143) is positioned in a floating state between the first magnet member (141) and the second magnet member (142), so that magnetic repulsion acts in multiple stages, thereby having the effect of cushioning the pressure more uniformly and finely than in the case of a single pair of magnets.

[0096] FIG. 5 is a cross-sectional view AA' of the laser welding pressure jig (100) of FIG. 2. FIG. 6 is a top view of the laser welding pressure jig (100) of FIG. 2.

[0097] The overall configuration of the pressure jig (100) for laser welding according to the first embodiment of the present invention has been described above. Below, with reference to FIGS. 5 and FIGS. 6, the detailed configuration of the jig body (110) according to the first embodiment of the present invention will be described. In FIGS. 5, the interior of the linear guide (120) is also additionally shown to facilitate the explanation.

[0098] Meanwhile, since a plurality of busbars (2) with different arrangement directions can be arranged on the battery cell (1) stack, a configuration is required that allows the direction of the pressure block (130) to be adjusted in correspondence with the arrangement direction of the busbars (2).

[0099] To this end, the jig body (110) may include a base part (110a) and a rotating part (110b).

[0100] The base portion (110a) is formed to be movable on the bus bar (2) and may have a first laser hole (110a1) that forms at least a part of the laser hole (111).

[0101] The rotating part (110b) may be provided with a second laser hole (110b11) that is rotatably coupled to the base part (110a) and communicates with the first laser hole (110a1) to form at least another part of the laser hole (111).

[0102] Additionally, the linear guide (120) is mounted on the pivot part (110b) so that the direction of the pressure block (130) can be aligned by relative rotation to correspond to the arrangement direction of the bus bar (2).

[0103] Meanwhile, the jig body (110) may further include a power transmission unit (110c) and a power receiving unit (110d).

[0104] The power transmission unit (110c) may be coupled to the base portion (110a) and configured to transmit the driving force required for relative rotation.

[0105] The power receiving unit (110d) is positioned between the base part (110a) and the rotating part (110b) and can be configured to receive driving force from the power transmission unit (110c) to rotate the rotating part (110b). To this end, it is preferable that at least one bearing be provided at the joint end of the power receiving unit (110d) and the base part (110a).

[0106] For example, a through hole may be formed in the power receiving unit (110d) that penetrates the central portion and connects the first laser hole (110a1) and the second laser hole (110b11).

[0107] The power transmission unit (110c) may be equipped with a motor bracket (110c1), a rotary motor (110c2), and a timing belt (110c3).

[0108] The motor bracket (110c1) is coupled to the base portion (110a), and the rotary motor (110c2) is mounted on the motor bracket (110c1) and can be spaced laterally from the rotating portion (110b).

[0109] For example, a power transmission member (110c21) may be mounted on the rotary motor (110c2).

[0110] The power transmission member (110c21) may be a timing pulley that rotates by the rotation of a rotary motor (110c2).

[0111] The timing belt (110c3) can be formed to connect the rotary motor (110c2) and the power receiving unit (110d) to transmit the driving force generated by the rotation of the rotary motor (110c2) to the power receiving unit (110d).

[0112] More specifically, the connection between the rotary motor (110c2) and the power receiving unit (110d) by the timing belt (110c3) can be made by the power transmission member (110c21) described above.

[0113] For example, one part of the timing belt (110c3) is engaged with a power receiving unit (110d), and another part of the timing belt (110c3) is engaged with a power transmission member (110c21), so that when the rotary motor (110c2) rotates, driving force can be transmitted to the power receiving unit (110d) through the timing belt (110c3).

[0114] Meanwhile, the base part (110a) may be equipped with a fume suction part (110a2) for suctioning fumes generated during laser welding of the bus bar (2) and the battery cell (1) and discharging them to the outside.

[0115] For example, the fume suction part (110a2) may include a fume discharge port (110a21) connected to a suction device.

[0116] More specifically, a fume discharge hole (110a3) penetrating the inner wall and the outer wall may be formed in the base portion (110a), and a fume discharge port (110a21) may be coupled to cover the opening of the fume discharge hole (110a3) formed in the outer wall of the base portion (110a).

[0117] Meanwhile, the rotating part (110b) according to the present embodiment may be equipped with a rotating housing (110b1), a pressure plate (110b2), and a sensing unit (110b3).

[0118] The rotating housing (110b1) is coupled to the lower part of the power receiving unit (110d) and is configured to rotate relative to the base part (110a), and may be formed in a hollow shape and have an internal space defined by an outer wall and an inner wall.

[0119] For example, the second laser hole (110b11) can be defined by the internal space of the rotating housing (110b1). That is, the hollow internal space of the rotating housing (110b1) itself can form an optical path through which the laser passes.

[0120] The pressure plate (110b2) is supported by the lower inner wall of the rotation housing (110b1) while being placed in the internal space of the rotation housing (110b1), and the guide housing (120a2, 120b2) of the linear guide (120) can be coupled to the lower part of the pressure plate (110b2).

[0121] At this time, the shaft (120a1, 120b1) can be positioned to protrude downward from the rotating housing (110b1) through the lower opening of the rotating housing (110b1) while at least a portion of it is inserted into the guide housing (120a2, 120b2).

[0122] The sensing unit (110b3) may be interposed between the upper inner wall of the rotating housing (110b1) and the pressure plate (110b2). For example, the sensing unit (110b3) may be a load cell equipped with a strain gauge.

[0123] More specifically, when the pressure block (130) presses the bus bar (2), the load cell between the upper inner wall of the rotating housing (110b1) and the pressure plate (110b2) is pressed by the reaction force transmitted from the bus bar (2), so that the strain gauge can be physically deformed.

[0124] At this time, the load cell can be configured to detect the pressure applied to the bus bar (2) based on the change in resistance value according to the deformation of the strain gauge.

[0125] Here, the pressure applied to the busbar (2) may mean a pressure buffered by magnetic repulsion acting between a plurality of magnetic members (140).

[0126] Meanwhile, a through hole is formed through the central portion of each of the sensing unit (110b3) and the pressure plate (110b2), and the sensing unit (110b3) and the pressure plate (110b2) may be arranged so that their through holes communicate with each other within the internal space of the rotating housing (110b1). At this time, each of the communicated through holes may be configured to limit the optical path of the second laser hole (110b11).

[0127] With this configuration, the laser can sequentially pass through the first laser hole (110a1), the through hole of the power receiving unit (110d), and the second laser hole (110b11) to reach the welding hole (130a1, 130b1).

[0128] At this time, the light path of the second laser hole (110b11) is limited by the through hole of the sensing unit (110b3) and the pressure plate (110b2), so that the laser can pass through the second laser hole (110b11) and be irradiated to the welding location without interfering with the sensing unit (110b3) and the pressure plate (110b2).

[0129] That is, the laser hole (111) can be defined as a single laser path formed by a communication structure of a first laser hole (110a1), a through hole of a power receiving unit (110d), and a second laser hole (110b11) in which the optical path is limited by a through hole of a sensing unit (110b3) and a pressure plate (110b2).

[0130] According to the detailed configuration of the jig body (110) described above, the direction of the pressure block (130) can be aligned to correspond to the arrangement direction of the bus bar (2) by the relative rotation of the pivot part (110b) with respect to the base part (110a), so that a pressure operation can be flexibly performed even for a plurality of bus bars (2) with different arrangement directions.

[0131] In addition, the rotation of the rotating part (110b) can be precisely controlled by the linkage of the power transmission unit (110c) and the power receiving unit (110d), and the light path of the second laser hole (110b11) is limited by the through hole of the sensing unit (110b3) and the pressure plate (110b2), so that the laser can stably pass through the second laser hole (110b11) without interference due to the internal configuration of the rotating part (110b) and be irradiated to the welding position.

[0132] FIG. 7 is an overall configuration diagram of a pressure jig (200) for laser welding according to a second embodiment of the present invention. FIG. 8 is an example diagram of the operation of the pressure jig (200) for laser welding of FIG. 7.

[0133] The above describes a pressure jig (100) for laser welding according to the first embodiment of the present invention, and below, with reference to FIGS. 7 and FIGS. 8, the overall configuration of a pressure jig (200) for laser welding according to the second embodiment of the present invention will be described.

[0134] It is preferable that the pressure jig (200) for laser welding be configured to precisely maintain the pressure applied to the busbar (2) at a preset target pressure to ensure uniform welding quality.

[0135] In this case, if a physical cushioning means, such as an elastic member like a spring, is intended to be used as a means of adjusting the pressure, the range of the pressure is determined by the physical properties of the elastic member; therefore, it is difficult to arbitrarily set or change the range of the pressure, and it may be difficult to precisely maintain the target pressure or reproduce the same pressure conditions.

[0136] Accordingly, a configuration is required that can realize constant pressure pressurization by feedback-controlling the pressurizing force without using physical cushioning means such as elastic members like springs.

[0137] To this end, a pressure jig (200) for laser welding according to a second embodiment of the present invention comprises a jig body (210), a linear driving unit (220), a pressure block (230), and a sensing unit (240).

[0138] Here, the jig body (210) and the pressure block (230) according to the present embodiment may have a configuration that partially corresponds to the configuration of the jig body (110) and the pressure block (130) according to the first embodiment. Accordingly, the description regarding the configuration that overlaps with the first embodiment is replaced by the above-mentioned content, and the following description focuses on the configuration that differs in the present embodiment.

[0139] However, unlike the first embodiment, this embodiment differs in that the pressure is applied not by the vertical movement of the jig body (210) itself, but by the movement of the moving rod (220a1, 220b1) by the linear driving unit (220) described later.

[0140] The linear drive unit (220) is equipped with a moving rod (220a1, 220b1) that is mounted on the jig body (210) and formed to be movable in the axial direction.

[0141] More specifically, referring to FIG. 8, the linear drive unit (220) may have a drive housing (220a2, 220b2) that accommodates at least a portion of a moving rod (220a1, 220b1) inside.

[0142] Additionally, the moving rod (220a1, 220b1) may be formed to be movable so as to protrude outward from the driving housing (220a2, 220b2) along the axial direction or to be movable so as to be drawn into the driving housing (220a2, 220b2). Meanwhile, in FIG. 8, some components have been omitted or simplified for convenience of explanation.

[0143] The pressure block (230) is coupled to the end of the moving rod (220a1, 220b1) and is configured to press the bus bar (2) by the movement of the moving rod (220a1, 220b1), and has a welding hole (230a1, 230b1) that guides the laser passing through the laser hole (211) in the pressurized state to the welding position of the positive part (21) and the negative part (22).

[0144] The sensing unit (240) is installed in at least one of the jig body (210) and the linear driving unit (220) to detect the pressure applied to the bus bar (2).

[0145] Additionally, based on the detection result of the sensing unit (240), the movement of the moving rod (220a1, 220b1) is feedback controlled so that the pressure applied to the bus bar (2) is maintained at a preset target pressure.

[0146] Accordingly, the laser welding pressure jig (200) according to the present embodiment can precisely maintain the pressure applied to the bus bar (2) at a preset target pressure by feedback controlling the movement of the moving rod (220a1, 220b1) based on the detection result of the sensing unit (240) without physical cushioning means such as an elastic member such as a spring.

[0147] In addition, it is possible to respond to various pressurization conditions simply by changing the set value of the target pressurization, and it has the effect of reducing pressurization fluctuations caused by the time-dependent deterioration of the physical buffering means.

[0148] For example, the movement of the moving rod (220a1, 220b1) is achieved by supplying a driving medium to the linear driving unit (220), and based on the detection result of the sensing unit (240), the supply of the driving medium is adjusted in real time so that the movement of the moving rod (220a1, 220b1) can be feedback controlled.

[0149] More specifically, when the pressure block (230) is in contact with one side of the bus bar (2) by the moving rod (220a1, 220b1), the supply of the driving medium can be adjusted in real time so that the pressure applied to the bus bar (2) by the pressure block (230) gradually increases.

[0150] Subsequently, during the process of gradually increasing the pressure, based on the detection result of the sensing unit (240), when the pressure applied to the bus bar (2) reaches a preset target pressure, the supply of the driving medium can be finely adjusted so that the target pressure is maintained.

[0151] More specifically, based on the difference between the detection result of the sensing unit (240) and the preset target pressure, the supply, blocking, and supply amount of the driving medium are adjusted so that the movement amount of the moving rod (220a1, 220b1) can be feedback controlled.

[0152] That is, when the current pressure detected by the sensing unit (240) is lower than the target pressure, the supply amount of the driving medium is increased, when the current pressure is higher than the target pressure, the supply amount of the driving medium is reduced or cut off, and when the current pressure reaches the target pressure, the supply amount of the driving medium can be finely adjusted to be maintained at the current level.

[0153] According to the feedback control described above, the supply of the driving medium is finely adjusted in real time based on the difference between the detection result of the sensing unit (240) and the target pressure, so the pressure can be maintained at a constant target pressure despite the shape deviation of the bus bar (2) or the height deviation of the battery cell (1).

[0154] In this embodiment, the linear drive unit (220) is preferably at least one of a pneumatic cylinder, a hydraulic cylinder, and an electric cylinder driven by the supply of the drive medium.

[0155] For example, if the linear drive unit (220) is a pneumatic cylinder or a hydraulic cylinder, the driving medium supplied to the linear drive unit (220) may be air or a working fluid, and the sensing unit (240) may be a pressure transducer installed in the pneumatic cylinder or hydraulic cylinder.

[0156] The pressure transducer may be configured to detect the pressure applied to the busbar (2) based on the pressure change in the inner chamber of the pneumatic cylinder or hydraulic cylinder.

[0157] As another example, if the linear drive unit (220) is an electric cylinder, the driving medium supplied to the linear drive unit (220) may be an electric current, and the sensing unit (240) may be a load cell installed in the jig body (210).

[0158] The load cell may be configured to detect the pressure applied to the bus bar (2) based on the change in resistance value due to deformation of the strain gauge, but the description thereof is the same as that described in the first embodiment and is replaced by the above description.

[0159] For convenience of explanation, the drawings are illustrated with the sensing unit (240) being a pressure transducer, but the sensing unit (240) may be selectively applied as a pressure transducer or a load cell depending on the driving method of the linear driving unit (220), and its installation location and shape are not limited to the illustrated examples.

[0160] FIG. 9 is a cross-sectional view of BB' of the laser welding pressure jig (200) of FIG. 7.

[0161] The overall configuration of the pressure jig (200) for laser welding according to the second embodiment of the present invention has been described above. Below, with reference to FIG. 9, the detailed configuration of the jig body (210) according to the second embodiment of the present invention will be described. In FIG. 9, the interior of the linear drive unit (220) is also additionally shown to facilitate the explanation.

[0162] Meanwhile, the jig body (210) may include a base part (210a), a rotating part (210b), a power transmission unit (210c), and a power receiving unit (210d), and the power transmission unit (210c) may be equipped with a motor bracket (210c1), a rotary motor (210c2), a power transmission member (210c21), and a timing belt (210c3), and the base part (210a) may be equipped with a fume suction part (210a2) for discharging fumes generated during laser welding to the outside, but since the description thereof is the same as that described in the first embodiment, it is replaced by the above description.

[0163] Meanwhile, the rotating part (210b) according to the present embodiment may be provided with a rotating housing (210b1).

[0164] The rotating housing (210b1) is coupled to the lower part of the power receiving unit (210d) and is configured to be rotatable relative to the base part (210a), and the second laser hole (210b11) communicating with the first laser hole (210a1) provided in the base part (210a) can be defined by the internal space of the rotating housing (210b1).

[0165] Additionally, as described above, a through hole may be formed in the power receiving unit (210d) that penetrates the central portion and connects the first laser hole (210a1) and the second laser hole (210b11).

[0166] That is, the laser hole (211) in the present embodiment can be defined as a single laser path formed by the communication structure of the first laser hole (210a1), the through hole of the power receiving unit (210d), and the second laser hole (210b11).

[0167] The linear drive unit (220) is mounted on the pivot part (210b), and the direction of the pressure block (230) can be aligned to correspond to the arrangement direction of the bus bar (2) by the relative rotation of the pivot part (210b) with respect to the base part (210a).

[0168] According to the detailed configuration of the jig body (210) of the second embodiment described above, the direction of the pressure block (230) can be aligned to correspond to the arrangement direction of the bus bar (2) through the relative rotation of the pivot part (210b) with respect to the base part (210a).

[0169] In addition, the optical path of the laser can be stably secured through a structure in which the first laser hole (210a1), the through hole of the power receiving unit (210d), and the second laser hole (210b11) are in communication with each other, and precise static pressure application to the bus bar (2) can be achieved in conjunction with the feedback control of the linear driving unit (220).

[0170] FIG. 10 (a) is a perspective view showing the upper structure of the pressure block (130, 230), and (b) is a perspective view showing the lower structure of the pressure block (130, 230). FIG. 11 is a conceptual diagram showing the pressure block (130, 230) of FIG. 10 pressing the bus bar (2).

[0171] The above describes a pressure jig (200) for laser welding according to the second embodiment of the present invention. Below, with reference to FIGS. 10 and FIGS. 11, the detailed configuration of the pressure block (130, 230) of the pressure jig (100, 200) for laser welding according to the first and second embodiments of the present invention will be described.

[0172] Meanwhile, the pressure jig (100, 200) for laser welding is required to have a configuration that can stably press each of the anode (21) and cathode (22) in correspondence with different shapes and heights, while accurately guiding the laser to the welding position.

[0173] Hereinafter, there is a difference in that in the first embodiment, the pressure block (130) is coupled to the end of the shaft (120a1, 120b1), and in the second embodiment, the pressure block (230) is coupled to the end of the movable rod (220a1, 220b1), but the detailed configuration of the pressure block (130, 230) can be applied commonly to both embodiments.

[0174] The pressure block (130, 230) includes a first pressure block (130a, 230a) and a second pressure block (130b, 230b) that respectively pressure the positive electrode (21) and the negative electrode (22), and the first pressure block (130a, 230a) and the second pressure block (130b, 230b) can be formed to interlock with each other.

[0175] Here, the first pressure block (130a) and the second pressure block (130b) according to the first embodiment may be configured to press the positive part (21) and the negative part (22) respectively according to the movement of the jig body (110), and the first pressure block (230a) and the second pressure block (230b) according to the second embodiment may be configured to press the positive part (21) and the negative part (22) respectively according to the movement of the moving rod (220a1, 220b1).

[0176] The welding hole may include a first welding hole (130a1, 230a1) and a second welding hole (130b1, 230b1) formed through the first pressure block (130a, 230a) and the second pressure block (130b, 230b), respectively.

[0177] More specifically, the first welding hole (130a1, 230a1) can be formed through the first pressure block (130a, 230a) to guide the laser passing through the laser hole (111, 211) to the welding position of the anode (21) while the first pressure block (130a, 230a) is pressing the anode (21).

[0178] The second welding hole (130b1, 230b1) can be formed through the second pressure block (130b, 230b) to guide the laser passing through the laser hole (111, 211) to the welding position of the cathode part (22) while the second pressure block (130b, 230b) is pressing the cathode part (22).

[0179] In addition, in the interlocking state of the first pressure block (130a, 230a) and the second pressure block (130b, 230b), the perimeter of the second welding hole (130b1, 230b1) may be arranged to surround at least a portion of the perimeter of the first welding hole (130a1, 230a1).

[0180] On the mutually opposing sides of the first pressure block (130a, 230a) and the second pressure block (130b, 230b), a coupling protrusion (130a2, 230a2) and a coupling groove (130b2, 230b2) may be formed, respectively.

[0181] The coupling protrusion (130a2, 230a2) is formed to protrude laterally from the side of the first pressure block (130a, 230a), and the coupling groove (130b2, 230b2) can be formed concavely in a shape corresponding to the coupling protrusion (130a2, 230a2) on the side of the second pressure block (130b, 230b) which is positioned to face the side of the first pressure block (130a, 230a).

[0182] For example, the coupling protrusion (130a2, 230a2) may be formed to form the outer surface of the first welding hole (130a1, 230a1) on the side of the first pressure block (130a, 230a), and the coupling groove (130b2, 230b2) may be formed to be wrapped by the second welding hole (130b1, 230b1) on the side of the second pressure block (130b, 230b).

[0183] At this time, when the coupling protrusions (130a2, 230a2) are inserted into the coupling grooves (130b2, 230b2) in an interlocking state, the outer surface of the first welding hole (130a1, 230a1) may be defined by the coupling grooves (130b2, 230b2) so that at least a portion of the perimeter of the first welding hole (130a1, 230a1) is wrapped by the second welding hole (130b1, 230b1).

[0184] Accordingly, in an interlocking state where the coupling protrusions (130a2, 230a2) are inserted into the coupling grooves (130b2, 230b2), the first pressure block (130a, 230a) and the second pressure block (130b, 230b) can be formed to form a single pressure block (130, 230) while restricting relative movement in the horizontal direction.

[0185] Meanwhile, the positive electrode (11) and the negative electrode (12) of the battery cell (1) may be formed at different heights. For example, the positive electrode (11) of the battery cell (1) may be formed to protrude by a first height from the upper center of the battery cell (1), and the negative electrode (12) of the battery cell (1) may be formed to protrude by a second height from the upper circumference of the battery cell (1), which is referred to as the shoulder. Here, the first height may be greater than the second height.

[0186] Additionally, the positive electrode (21) and the negative electrode (22) are arranged to cover the positive electrode (11) and the negative electrode (12), which are formed at different heights in the battery cell (1), respectively, thereby forming a predetermined height step. At this time, the first pressure block (130a, 230a) and the second pressure block (130b, 230b) may be formed to be mutually separable so as to be able to press the positive electrode (21) and the negative electrode (22), respectively, in correspondence with the height step.

[0187] Meanwhile, in an interlocking state where the coupling protrusions (130a2, 230a2) are inserted into the coupling grooves (130b2, 230b2), the first pressure block (130a, 230a) and the second pressure block (130b, 230b) may be configured to allow relative movement along the vertical direction while restricting relative movement in the horizontal direction.

[0188] That is, the contact surface of the coupling protrusion (130a2, 230a2) and the coupling groove (130b2, 230b2) functions as a sliding guide surface along the vertical direction, so that at least a part of the first pressure block (130a, 230a) and at least a part of the second pressure block (130b, 230b) can slide vertically relative to each other while maintaining interlocking.

[0189] The first pressure block (130a, 230a) and the second pressure block (130b, 230b) described above are formed to be separable by moving relative to each other in the vertical direction while being constrained in the horizontal direction by the coupling protrusion (130a2, 230a2) and the coupling groove (130b2, 230b2), thereby overcoming the height difference between the positive electrode (21) and the negative electrode (22) and stably applying pressure to the positive electrode (21) and the negative electrode (22), respectively.

[0190] Hereinafter, each embodiment of the present invention is described based on the configuration of the first pressure block (130a, 230a) and the second pressure block (130b, 230b) described above.

[0191] In the first embodiment, the lower surface of the first pressure block (130a) may be provided with a first pressure protrusion (130a11) that is formed to protrude around the first welding hole (130a1) and is configured to press the anode portion (21) by the movement of the jig body (110).

[0192] On the lower surface of the second pressure block (130b), a second pressure protrusion (130b11) may be provided, which is formed to protrude around the second welding hole (130b1) and pressurize the negative electrode (22) by the movement of the jig body (110).

[0193] Additionally, the linear guide (120) may include a first linear guide (120a) and a second linear guide (120b). (See FIG. 5 and FIG. 6)

[0194] More specifically, the first linear guide (120a) and the second linear guide (120b) can be spaced apart from each other with the laser hole (111) in between.

[0195] The first pressure block (130a) and the second pressure block (130b) can be respectively coupled to the ends of the shafts (120a1, 120b1) provided in the first linear guide (120a) and the second linear guide (120b).

[0196] Meanwhile, in this embodiment, a plurality of magnet members (140) described above may be fitted onto the outer surface of the shaft (120a1, 120b1) provided in each of the first linear guide (120a) and the second linear guide (120b).

[0197] More specifically, the first magnetic member (141) described above may be positioned to be fixed to the guide housing (120a2, 120b2) provided in each of the first linear guide (120a) and the second linear guide (120b) while being positioned at one end of the shaft (120a1, 120b1) provided in each of the first linear guide (120a) and the second linear guide (120b).

[0198] For example, one of the N poles and S poles of each of the first magnetic member (141) may be supported and fixed inside the guide housing (120a2, 120b2) provided in each of the first linear guide (120a) and the second linear guide (120b), and the other of the N poles and S poles may be arranged to protrude outside the guide housing (120a2, 120b2) provided in each of the first linear guide (120a) and the second linear guide (120b).

[0199] The above-described second magnetic member (142) is positioned at the other end of the shaft (120a1, 120b1) provided in each of the first linear guide (120a) and the second linear guide (120b), and can be supported by the first pressure block (130a) and the second pressure block (130b), respectively.

[0200] Additionally, each of the second magnetic members (142) can be configured to move relative to the first magnetic member (141) by the movement of the shafts (120a1, 120b1) provided in the first linear guide (120a) and the second linear guide (120b), respectively, while being supported by the first pressure block (130a) and the second pressure block (130b).

[0201] The above-described intermediate magnet member (143) can be positioned in a floating state between the first magnet member (141) and the second magnet member (142) by means of magnetic repulsion acting between the plurality of magnet members (140) while being fitted onto shafts (120a1, 120b1) provided in each of the first linear guide (120a) and the second linear guide (120b).

[0202] For example, the intermediate magnet member (143) may be provided in multiple numbers between the first magnet member (141) and the second magnet member (142) positioned at one end and the other end of the shaft (120a1, 120b1) provided in each of the first linear guide (120a) and the second linear guide (120b).

[0203] Meanwhile, each of the first linear guide (120a) and the second linear guide (120b) may be provided in multiple numbers.

[0204] More specifically, a part of the first pressure block (130a) may be coupled to the end of the shaft (120a1) provided in one of the plurality of first linear guides (120a), and another part of the first pressure block (130a) may be coupled to the end of the shaft (120a1) provided in another of the plurality of first linear guides (120a).

[0205] Additionally, a portion of the second pressure block (130b) may be coupled to the end of the shaft (120b1) provided in one of the plurality of second linear guides (120b), and another portion of the second pressure block (130b) may be coupled to the end of the shaft (120b1) provided in another of the plurality of second linear guides (120b).

[0206] At this time, the plurality of magnetic members (140) fitted into the shafts (120a1) provided in each of the plurality of first linear guides (120a) are formed to have the same magnetic properties, and the plurality of magnetic members (140) fitted into the shafts (120b1) provided in each of the plurality of second linear guides (120b) can be formed to have the same magnetic properties.

[0207] Accordingly, by means of a plurality of magnetic members (140), the buffering of the pressure applied to each of the positive electrode (21) and the negative electrode (22) can be maintained uniformly.

[0208] For example, when the first pressure block (130a) and the second pressure block (130b) apply pressure to the positive portion (21) and the negative portion (22), the spacing distance between the plurality of magnetic members (140) fitted onto the shaft (120a1) provided in the first linear guide (120a) and the spacing distance between the plurality of magnetic members (140) fitted onto the shaft (120b1) provided in the second linear guide (120b) may be formed differently from each other.

[0209] For example, as described above, when the anode (11) and the cathode (12) form a certain height difference due to the height difference between the anode (11) and the cathode (12), the anode (21) is at a higher position than the cathode (22), so the shaft (120a1) provided in the first linear guide (120a) can be moved further upward than the shaft (120b1) provided in the second linear guide (120b) by the pressure of the anode (21).

[0210] At this time, a plurality of intermediate magnet members (143) fitted onto shafts (120a1, 120b1) provided in each of the first linear guide (120a) and the second linear guide (120b) slide in the axial direction corresponding to the travel distance of each shaft (120a1, 120b1), and by sliding, the spacing distance between the plurality of intermediate magnet members (143) fitted onto each shaft (120a1, 120b1) is formed differently from each other, and the magnetic repulsion force can also be formed differently from each other.

[0211] Accordingly, the pressure applied to each of the positive electrode (21) and the negative electrode (22) can be independently buffered in correspondence with the height difference, so that uneven transmission of the pressure can be prevented.

[0212] The first linear guide (120a) and the second linear guide (120b) in the first embodiment have been described above, and the first linear driving unit (220a) and the second linear driving unit (220b) in the second embodiment will be described below.

[0213] In the second embodiment, the lower surface of the first pressure block (230a) may be provided with a first pressure protrusion (230a11) that is formed to protrude around the first welding hole (230a1) and is configured to press the anode portion (21) by the movement of the moving rod (220a1).

[0214] On the lower surface of the second pressure block (230b), a second pressure protrusion (230b11) may be provided, which is formed to protrude around the second welding hole (230b1) and is configured to press the negative part (22) by the movement of the moving rod (220b1).

[0215] Additionally, the linear drive unit (220) may include a first linear drive unit (220a) and a second linear drive unit (220b). (See FIG. 8)

[0216] More specifically, the first linear drive unit (220a) and the second linear drive unit (220b) may be spaced apart from each other with a laser hole (211) in between.

[0217] The first pressure block (230a) and the second pressure block (230b) can be respectively coupled to the ends of the moving rods (220a1, 220b1) provided in the first linear drive unit (220a) and the second linear drive unit (220b).

[0218] Meanwhile, in the present embodiment, the sensing unit (240) may include a first sensing unit (241) and a second sensing unit (242).

[0219] At this time, the first linear drive unit (220a) and the second linear drive unit (220b) are pneumatic cylinders or hydraulic cylinders, and the first sensing unit (241) and the second sensing unit (242) may be pressure transducers.

[0220] The first sensing unit (241) may be installed in the first linear driving unit (220a) to detect the pressure applied to the positive electrode (21), and the second sensing unit (242) may be installed in the second linear driving unit (220b) to detect the pressure applied to the negative electrode (22).

[0221] Additionally, based on the detection results of the first sensing unit (241) and the second sensing unit (242), the movement of the moving rods (220a1, 220b1) provided in the first linear driving unit (220a) and the second linear driving unit (220b), respectively, can be individually feedback controlled.

[0222] More specifically, based on the difference between the pressure applied to the anode (21) detected by the first sensing unit (241) and the pressure applied to the cathode (22) detected by the second sensing unit (242), the supply of the driving medium supplied to the first linear driving unit (220a) and the second linear driving unit (220b) can be adjusted differently.

[0223] For example, the above difference value can be compared with a preset allowable pressure deviation corresponding to the height difference between the positive electrode (11) and the negative electrode (12).

[0224] More specifically, the absolute value of the difference between the pressure applied to the anode (21) detected by the first sensing unit (241) and the pressure applied to the cathode (22) detected by the second sensing unit (242) can be compared with a preset allowable pressure deviation.

[0225] If the absolute value of the above difference exceeds the above allowable pressure deviation, the amount of driving medium supplied to the side where a relatively high pressure is detected may be reduced, or the amount of driving medium supplied to the side where a relatively low pressure is detected may be increased.

[0226] If the absolute value of the above difference is less than or equal to the above allowable pressure deviation, the driving state of the first linear driving unit (220a) and the second linear driving unit (220b) can be maintained.

[0227] Meanwhile, each of the first linear drive unit (220a) and the second linear drive unit (220b) may be provided in multiple numbers.

[0228] More specifically, a part of the first pressure block (230a) may be coupled to the end of the moving rod (220a1) provided in any one of the plurality of first linear driving units (220a), and another part of the first pressure block (230a) may be coupled to the end of the moving rod (220a1) provided in another of the plurality of first linear driving units (220a).

[0229] Additionally, a portion of the second pressure block (230b) may be coupled to the end of the moving rod (220b1) provided in any one of the plurality of second linear driving units (220b), and another portion of the second pressure block (230b) may be coupled to the end of the moving rod (220b1) provided in another of the plurality of second linear driving units (220b).

[0230] At this time, a plurality of first linear drive units (220a) may be supplied with a driving medium of the same type, and a plurality of second linear drive units (220b) may be supplied with a driving medium of the same type.

[0231] Accordingly, the pressure applied to the positive electrode (21) and the negative electrode (22), respectively, by the first sensing unit (241) and the second sensing unit (242) is independently detected, and the supply of the driving medium supplied to the plurality of first linear driving units (220a) and the plurality of second linear driving units (220b) is individually feedback controlled based on the detection results, so that the balance of the pressure applied to the positive electrode (21) and the negative electrode (22), respectively, is maintained in correspondence with the height difference, thereby preventing the bus bar (2) from lifting or tilting.

[0232] FIG. 12 is a block diagram showing the configuration of a laser welding system (1000, 2000) according to a first embodiment and a second embodiment. FIG. 13 is a block diagram showing the feedback control of a control unit (2000a) according to a second embodiment.

[0233] In the above description, a pressure jig (100, 200) for laser welding according to the first and second embodiments of the present invention has been described. Below, with reference to FIGS. 12 and FIGS. 13, a laser welding system (1000, 2000) according to the first and second embodiments of the present invention will be described.

[0234] The laser welding system (1000, 2000) includes a pressure jig (100, 200) for laser welding, a laser scanner (1100, 2100), and a control unit (1000a, 2000a).

[0235] Here, the laser welding pressure jig (100, 200) may be a laser welding pressure jig (100, 200) according to either the first embodiment or the second embodiment described above. Accordingly, content that overlaps with the above description is omitted as much as possible.

[0236] For example, a pressure jig (100, 200) for laser welding can be mounted on a work robot (not shown), such as a manipulator or an autonomous mobile robot (AMR), and can be configured to move along a preset work path on the upper part of a bus bar (2) placed on a battery cell (1) to perform a pressure operation during laser welding.

[0237] For example, a work robot (not shown) may be configured to move a laser welding pressure jig (100, 200) in the X, Y, and Z directions. That is, the laser welding pressure jig (100, 200) may be configured to perform the role of an end effector of the work robot (not shown).

[0238] The laser scanner (1100, 2100) is formed to irradiate a laser when the laser welding pressure jig (100, 200) pressurizes the bus bar (2) so as to laser weld the positive part (21) and the negative part (22) to the positive part (11) and the negative part (12), respectively.

[0239] For example, the laser scanner (1100, 2100) may be configured to move to the position of the laser welding target in response to the movement of the pressure jig (100, 200) for laser welding.

[0240] Additionally, the laser irradiated through the laser scanner (1100, 2100) can be guided to the welding positions of the anode (21) and cathode (22) by the first welding hole (130a1, 230a1) and the second welding hole (130b1, 230b1) after passing through the laser hole (111, 211).

[0241] For example, the laser scanner (1100, 2100) may be equipped with two light sources formed to irradiate a laser to the first welding hole (130a1, 230a1) and the second welding hole (130b1, 230b1), respectively.

[0242] In this case, lasers irradiated from two light sources can pass through the first welding hole (130a1, 230a1) and the second welding hole (130b1, 230b1), respectively, and be irradiated at the welding positions of the anode (21) and the cathode (22).

[0243] As another example, the laser scanner (1100, 2100) is equipped with a single light source, and the irradiation position of the laser irradiated from the single light source can be sequentially changed to correspond to the first welding hole (130a1, 230a1) and the second welding hole (130b1, 230b1).

[0244] In this case, the laser can pass through the first welding hole (130a1, 230a1) and the second welding hole (130b1, 230b1) sequentially and be irradiated at the welding positions of the anode (21) and the cathode (22), respectively.

[0245] The control unit (1000a, 2000a) is configured to monitor the pressure applied to the busbar (2) and, based on this, to control the pressure jig (100, 200) for laser welding and the laser scanner (1100, 2100).

[0246] The control unit (1000a, 2000a) may be a PLC (Programmable Logic Controller). However, it is not limited thereto, and the control unit (1000a, 2000a) may be implemented as various types of control devices such as an industrial computer (IPC: Industrial PC) or a microcontroller unit (MCU: Microcontroller Unit).

[0247] For example, in the case of a pressure jig (100) for laser welding according to the first embodiment, the Z-axis movement of a working robot (not shown) is controlled by a control command of a control unit (1000a), thereby controlling the vertical movement amount of the jig body (110), and accordingly, the pressure applied to the bus bar (2) can be controlled.

[0248] More specifically, when the pressure block (130) pressurizes the bus bar (2), the control unit (1000a) may be configured to monitor the pressure applied to the bus bar (2) based on the change in resistance value according to the deformation of the strain gauge detected by the sensing unit (110b3). At this time, the monitoring result may be provided to the user in real time through a terminal or the like.

[0249] As another example, referring to FIG. 13, in the case of a laser welding pressure jig (200) according to the second embodiment, the axial movement of the moving rod (220a1, 220b1) is feedback controlled by a control command of the control unit (2000a), so that the pressure applied to the bus bar (2) can be controlled.

[0250] More specifically, when the pressurizing block (230) pressurizes the busbar (2), the control unit (2000a) may be configured to monitor the pressure applied to the busbar (2) based on the detection result of the sensing unit (240). At this time, the monitoring result may be provided to the user in real time through a terminal or the like.

[0251] Additionally, the control unit (2000a) can feedback control the movement of the moving rod (220a1, 220b1) so that the pressure applied to the bus bar (2) is maintained at a preset target pressure by adjusting the supply of the driving medium in real time based on the monitoring results.

[0252] To this end, the laser welding system according to the second embodiment may further include a regulator (2200).

[0253] In this case, the supply amount of the driving medium can be controlled by a regulator (2200) installed on the supply line of the driving medium.

[0254] For example, the regulator (2200) may be at least one of a pressure regulator that regulates the supply amount of a driving medium supplied to a pneumatic cylinder or a hydraulic cylinder, and a voltage regulator that regulates the supply amount of a driving medium supplied to an electric cylinder.

[0255] The pressure regulator may be an electronic proportional pressure regulator or a proportional pressure control valve configured to regulate the pressure of air or working fluid supplied to a pneumatic cylinder or a hydraulic cylinder.

[0256] The voltage regulator may be a voltage converter positioned on a power line supplied to an electric cylinder, configured to increase, maintain, and decrease the current supplied to the electric cylinder by converting the input voltage to a set voltage or adjusting the output voltage.

[0257] In this case, the control unit (2000a) can feedback control the movement of the moving rod (220a1, 220b1) by controlling the operation of the regulator (2200) to regulate the supply of the driving medium.

[0258] More specifically, the control unit (2000a) can adjust the supply of the driving medium to the first linear driving unit (220a) and the second linear driving unit (220b), respectively, based on the difference between the pressure applied to the positive electrode (21) detected by the first sensing unit (241) and the pressure applied to the negative electrode (22) detected by the second sensing unit (242).

[0259] Meanwhile, the laser welding system (1000, 2000) may further include a vision sensor (1000b, 2000b) configured to detect the welding position of each bus bar (2).

[0260] The vision sensor (1000b, 2000b) may be configured to detect the positions of the positive portion (21) and the negative portion (22) of the bus bar (2) placed on the battery cell (1) stack. For example, the vision sensor (1000b, 2000b) may be any one of a CCD camera, a CMOS camera, a line scan camera, and a 3D vision camera.

[0261] Additionally, the control unit (1000a, 2000a) can plan the operation schedule of the laser welding pressure jig (100, 200) and the laser scanner (1100, 2100) based on the positions of the positive electrode (21) and the negative electrode (22) detected by the vision sensor (1000b, 2000b), and generate control commands for the same.

[0262] For example, the control command may include at least one of the movement path, pressure position, pressure sequence, and pressure timing of the pressure jig (100, 200) for laser welding, and the laser welding position, laser welding sequence, and laser welding timing of the laser scanner (1100, 2100).

[0263] As another example, the control unit (1000a, 2000a) can generate control commands for the operation schedule of the laser welding pressure jig (100, 200) and the laser scanner (1100, 2100) based on a preset operation schedule.

[0264] Accordingly, the pressing operation of the laser welding pressurizing jig (100, 200) and the welding of the laser scanner (1100, 2100) are linked by a control command based on a planned work schedule, so that the welding of the battery cell (1) and the bus bar (2) can be performed on-the-fly.

[0265] In the above description, a laser welding system (1000, 2000) according to the first and second embodiments of the present invention has been described, and below, a laser welding method using the laser welding system (1000, 2000) according to the first and second embodiments of the present invention will be described.

[0266] Meanwhile, a laser welding method is required that can laser weld the positive electrode (21) and the negative electrode (22) to the positive electrode (11) and the negative electrode (12) of the battery cell (1), respectively, while the busbar (2) is stably pressurized.

[0267] A laser welding method using a laser welding system (1000) according to a first embodiment includes the following steps. (See FIG. 3)

[0268] (a) A step of placing a pressure jig (100) for laser welding on a busbar (2) may be performed.

[0269] For example, in step (a) above, a pressure jig (100) for laser welding can be placed on the welding position of the bus bar (2) by a control command of the control unit (1000a).

[0270] Additionally, in step (a) above, the laser scanner (1100) may be positioned on the pressure jig (100) for laser welding so as to be able to irradiate a laser through the laser hole (111).

[0271] (b) A step of bringing the pressure block (130) into contact with the bus bar (2) may be performed.

[0272] For example, in step (b) above, while the direction of the pressure block (130) is aligned with the arrangement direction of the bus bar (2) by the rotation of the pivot part (110b), the pressure block (130) can come into contact with one surface of the bus bar (2) by the vertical movement of the jig body (110). At this time, the laser scanner (1100) can also be aligned in correspondence with the arrangement direction of the bus bar (2).

[0273] (c) While applying pressure to the busbar (2) with a pressure block (130), a step of laser welding the positive part (21) and the negative part (22) to the positive part (11) and the negative part (12), respectively, with a laser scanner (1100) can be performed.

[0274] In step (c) above, when the pressure block (130) presses the bus bar (2), the shaft (120a1, 120b1) moves toward the jig body (110) so that the distance between the plurality of magnetic members (140) decreases, and due to the decrease in the distance between the plurality of magnetic members (140), the magnetic repulsion force acting between each of the plurality of magnetic members (140) increases.

[0275] That is, in step (c) above, the pressure applied to the bus bar (2) can be cushioned by the magnetic repulsion force acting between the plurality of magnetic members (140) fitted into the shaft (120a1, 120b1).

[0276] According to the laser welding method according to the first embodiment described above, while the busbar (2) is stably pressed, the pressing force is buffered by the non-contact magnetic repulsion force acting between the plurality of magnetic members (140), and the positive part (21) and the negative part (22) can be laser welded to the positive part (11) and the negative part (12), respectively.

[0277] Hereinafter, a laser welding method using a laser welding system (2000) according to a second embodiment of the present invention will be described.

[0278] A laser welding method using a laser welding system (2000) according to a second embodiment may include steps (a) to (c) identical to steps (a) to (c) of a laser welding method using a laser welding system (1000) according to a first embodiment. Accordingly, the details regarding this are replaced by the description above. (See FIG. 8)

[0279] However, in step (b) of this embodiment, there is a partial difference from the first embodiment in that the moving rod (220a1, 220b1) moves by the driving medium supplied to the linear driving unit (220) so that the pressing block (230) can come into contact with one surface of the bus bar (2).

[0280] In addition, in step (c) above, the control unit (2000a) controls the supply of the driving medium in real time based on the detection result of the sensing unit (240) to provide feedback control of the movement of the moving rod (220a1, 220b1).

[0281] More specifically, in step (c) above, when the pressure applied to the busbar (2) reaches a preset target pressure based on the detection result of the sensing unit (240), laser welding by the laser scanner (2100) can be performed.

[0282] According to the laser welding method according to the second embodiment described above, laser welding can be performed while maintaining the pressure applied to the busbar (2) at a preset target pressure based on the detection result of the sensing unit (240), thereby reducing excessive application of pressure or uneven transmission, and thus ensuring the reproducibility and uniformity of the welding quality.

[0283] The foregoing description is merely illustrative, and various modifications may be made by those skilled in the art without departing from the scope and technical spirit of the described embodiments. The foregoing embodiments may be implemented individually or in any combination. Explanation of the symbols

[0284] 100: Pressure jig for laser welding according to the first embodiment 110: Jig body according to the first embodiment 120: Linear guide according to the first embodiment 130: Pressure block according to the first embodiment 140: A plurality of magnetic members according to the first embodiment 200: Pressure jig for laser welding according to the second embodiment 210: Jig body according to the second embodiment 220: Linear driving unit according to the second embodiment 230: Pressure block according to the second embodiment 240: Sensing unit according to the second embodiment

Claims

Claim 1 A pressure jig for laser welding to apply pressure to a busbar when laser welding the positive and negative portions of a busbar disposed on a battery cell stack to the positive and negative portions of the battery cell, respectively, comprises: a jig body spaced apart from the upper portion of the busbar, configured to be movable in a vertical direction, and having a laser hole formed to allow a laser to pass through; a linear guide mounted on the jig body and having a shaft configured to be movable in an axial direction; and a pressure block coupled to the end of the shaft, configured to apply pressure to the busbar by the movement of the jig body, and having a welding hole that guides the laser passing through the laser hole in the applied pressure state to the welding position of the positive portion and the negative portion. A pressure jig for laser welding, comprising a plurality of magnetic members spaced apart such that their identical poles face each other along the axial direction of the shaft while being fitted onto the shaft, wherein when the pressure block presses the bus bar, the shaft moves toward the jig body so that the spacing distance between the plurality of magnetic members decreases, and the magnetic repulsion force acting between each of the plurality of magnetic members increases due to the decrease in the spacing distance. Claim 2 A laser welding pressure jig according to claim 1, characterized in that when the pressure block presses the bus bar, the shaft is pressed by the reaction force transmitted from the bus bar and moves toward the jig body, and as the distance between the plurality of magnetic members decreases due to the movement of the shaft, the magnetic repulsion force increases and the pressure applied to the bus bar is buffered. Claim 3 A pressure jig for laser welding according to claim 2, wherein at least one of the plurality of magnet members is formed to be slidable along the axial direction while fitted onto the outer surface of the shaft, and as the shaft moves, at least one of the plurality of magnet members slides toward another adjacent one of the plurality of magnet members, thereby reducing the distance between the plurality of magnet members. Claim 4 A pressure jig for laser welding according to claim 2, wherein the plurality of magnet members comprises: a first magnet member disposed at one end of the shaft; a second magnet member disposed at the other end of the shaft and supported by one surface of the pressure block; and at least one intermediate magnet member disposed between the first magnet member and the second magnet member in a floating state due to the magnetic repulsion force and configured to slide along the axial direction. Claim 5 A pressure jig for laser welding according to claim 1, wherein the jig body comprises: a base portion having a first laser hole formed to be movably on the bus bar and forming at least a part of the laser hole; and a pivot portion having a second laser hole formed to be in communication with the first laser hole and forming at least another part of the laser hole, and wherein the linear guide is mounted on the pivot portion and is aligned such that the direction of the pressure block corresponds to the arrangement direction of the bus bar by the relative rotation. Claim 6 A pressure jig for laser welding according to claim 5, wherein the jig body further comprises: a power transmission unit coupled to the base portion and transmitting a driving force required for relative rotation; and a power receiving unit disposed between the base portion and the rotating portion, receiving a driving force from the power transmission unit and rotating the rotating portion. Claim 7 A pressure jig for laser welding according to claim 6, wherein the power transmission unit comprises: a motor bracket coupled to the base portion; a rotary motor mounted on the motor bracket and spaced laterally from the rotating portion; and a timing belt connecting the rotary motor and the power receiving unit to transmit the driving force generated by the rotary motor to the power receiving unit. Claim 8 A laser welding pressure jig according to claim 1, wherein the pressure block comprises a first pressure block and a second pressure block that respectively apply pressure to the anode and the cathode by the movement of the jig body, and the welding hole comprises a first welding hole and a second welding hole formed through the first pressure block and the second pressure block, respectively, and wherein the first pressure block and the second pressure block are formed to be interlockable with each other. Claim 9 A laser welding pressure jig according to claim 8, wherein the first welding hole is configured to guide a laser passing through the laser hole to a welding position of the anode while the first pressure block is pressing the anode, and the second welding hole is configured to guide a laser passing through the laser hole to a welding position of the cathode while the second pressure block is pressing the cathode, and wherein, in the interlocking state, the perimeter of the second welding hole is arranged to surround at least a portion of the perimeter of the first welding hole. Claim 10 A laser welding pressure jig according to claim 9, characterized in that the lower surface of the first pressure block is provided with a first pressure protrusion formed protruding from the periphery of the first welding hole to press the anode portion by the movement of the jig body, and the lower surface of the second pressure block is provided with a second pressure protrusion formed protruding from the periphery of the second welding hole to press the cathode portion by the movement of the jig body. Claim 11 A pressure jig for laser welding according to claim 8, wherein, in a state where the positive electrode and the negative electrode of the battery cell are formed at different heights, the positive electrode portion and the negative electrode portion are arranged to cover the positive electrode and the negative electrode, respectively, to form a predetermined height step, and the first pressure block and the second pressure block are formed to be mutually separable so as to be able to press the positive electrode portion and the negative electrode portion, respectively, in correspondence with the height step. Claim 12 A laser welding pressure jig according to claim 11, wherein the linear guide comprises a first linear guide and a second linear guide spaced apart from each other with the laser hole in between, and the first and second pressure blocks are each coupled to the ends of the shafts provided in the first and second linear guides, respectively. Claim 13 A laser welding pressure jig according to claim 12, characterized in that when the first pressure block and the second pressure block each apply pressure to the anode and the cathode, the spacing distance between the plurality of magnet members fitted into the shaft provided in the first linear guide and the spacing distance between the plurality of magnet members fitted into the shaft provided in the second linear guide are formed differently from each other. Claim 14 A laser welding system characterized by comprising: a pressure jig for laser welding according to any one of claims 1 to 13; and a laser scanner that irradiates a laser to sequentially pass through the laser hole and the welding hole when the pressure jig for laser welding presses the bus bar, thereby laser welding the anode and the cathode to the anode and the cathode, respectively. Claim 15 A laser welding method using a laser welding system according to claim 14, comprising: (a) a step of placing a pressure jig for laser welding on the busbar; (b) a step of bringing a pressure block into contact with the busbar; and (c) a step of laser welding the anode and the cathode to the anode and the cathode, respectively, using a laser scanner while applying pressure to the busbar with the pressure block, wherein in step (c), when the pressure block applies pressure to the busbar, the shaft moves toward the jig body so as to reduce the distance between the plurality of magnetic members, and the magnetic repulsion force acting between each of the plurality of magnetic members increases due to the reduction in the distance between them.

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