Linear track system

Abstract

Provided is a linear track system capable of controlling an object to be transferred to accurately reach a target position. The linear track system comprises: a rail having an electromagnet mounted along the longitudinal direction thereof; a mover which has a coil electromagnetically interacting with the electromagnet and moves along the longitudinal direction of the rail; and a control unit for controlling a current applied to the electromagnet to drive the mover. The reference position of the mover and the target position of a fixed jig are set on the rail. The mover is controlled to stop at the reference position, and the linear track system provides a detection unit for detecting a stop position of the fixed jig of the mover that has stopped at the reference position. The control unit controls a current applied to the electromagnet so that the mover stops at an offset stop position obtained by applying information about deviation between the stop position and the reference position of the fixed jig to the target position.

Description

linear track system

[0001] This application claims the benefit of priority from Republic of Korea Patent Application No. 10-2024-0095053, dated July 18, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a linear track system, and more particularly, to a linear track system that can be controlled so that a transport object accurately reaches a target position.

[0003] A linear track includes a rail having an electromagnet mounted along the longitudinal direction, a mover having a coil that electromagnetically interacts with the electromagnet and is driven by a current applied to the electromagnet to move along the longitudinal direction of the rail, and a control unit that controls the current applied to the electromagnet to drive the mover.

[0004] These linear tracks offer the advantages of fast mover movement speeds and precise control of the mover's position via current control. However, in actual operation, the mover's position on the linear track varies. While this variation is not significant, typically within 1 mm, it is difficult to adopt as a transport device for processes requiring more precise position control.

[0005] As demand for secondary batteries has recently increased rapidly, various types of secondary batteries are being developed.

[0006] Cylindrical battery cells house jelly-roll-shaped electrode assemblies within a cylindrical metal can, making them more shock- and temperature-resistant than pouch-type batteries. Consequently, demand for can-type cells in vehicle battery packs is growing.

[0007] Conventional can-shaped battery cells electrically connect the electrodes and the can or terminals by bonding a separate tab member to the current collector of the electrode assembly and bonding the tab member to the can or terminal. However, in battery cells with this structure, the structure for electrically connecting the electrodes and terminals takes up a significant amount of internal space within the can. Furthermore, this electrical connection structure has limitations in reducing internal resistance because the current path is limited to the tab member. An electrical connection structure that makes it difficult to reduce internal resistance is unsuitable for application to large-capacity battery cells that carry high currents.

[0008] To increase energy density, cylindrical battery cells are being developed with increasing volume. Furthermore, technological development is being focused on maximizing the internal space of cylindrical battery cells, maximizing the volume of the electrode assembly within the space. Furthermore, active technological development is underway to reduce the internal resistance between the electrodes and terminals or cans of the electrode assembly.

[0009] Accordingly, a structure has recently been developed in which a non-coated portion of the current collector is exposed to the axial end of the electrode assembly, folded in a radial direction so that the folded non-coated portion forms a flat surface facing the axial direction, a current collector plate is welded to the surface, and the current collector plate is again joined to a can or terminal. According to this structure, the current path between the electrode and the can or terminal is widened to lower the internal resistance, while the space inside the can occupied by the electrical connection structure between the electrode and the can or terminal is minimized, thereby further increasing the energy density of the battery cell.

[0010] However, in these recent battery cell structures, if the assembly positions of the current collector plates relative to the electrode assembly are not precisely aligned, misalignment problems arise in the welding positions of the current collector plates of the electrode assembly, misalignment problems also arise in the assembly positions of the can and the current collector plates, and further misalignment problems also arise in the welding positions of the can and the current collector plates. As a result, the welding of the current collector plates may be incomplete or weak, which may narrow the current path or increase the internal resistance.

[0011] The present invention has been devised to solve the above-described problems, and aims to provide a linear track system with further reduced transport deviation.

[0012] The present invention aims to provide a linear track system capable of precisely performing a welding assembly process of a current collector plate for an electrode assembly without precisely controlling the supply position of the current collector plate and the heating position for welding.

[0013] The present invention aims to provide a linear track system capable of increasing production speed by performing a welding assembly process of a current collector plate for an electrode assembly precisely and quickly.

[0014] The technical objectives of the present invention are not limited to the purposes mentioned above. Other objectives and advantages of the present invention not mentioned above can be understood through the following description and will be more clearly understood through the embodiments of the present invention. Furthermore, it will be readily apparent that the objectives and advantages of the present invention can be realized by the means and combinations thereof set forth in the claims.

[0015] The present invention can be applied to a linear track system including a rail extending along a predetermined path, a mover moving along the longitudinal direction of the rail by electromagnetic interaction with the rail, a fixing jig provided on the mover to fix a first component, and a control unit for driving the mover.

[0016] The above rail may be equipped with an electromagnet along its length.

[0017] The above mover has a coil that electromagnetically interacts with the electromagnet and is driven by a current applied to the electromagnet to move along the length of the rail.

[0018] The above control unit can control the operation of the mover by controlling the current applied to the electromagnet.

[0019] The arrival position of each mover can be precisely controlled by current control of the above control unit.

[0020] Even if the installation positions of the coils installed on each of the multiple movers are consistent, the alignment reference points of the coils that electromagnetically interact with the electromagnets of the rail may differ. In other words, even if the installation positions of the coils installed on each mover are precisely regulated, the positions of the reference points for the electromagnetic interaction between the coils and the electromagnets of the rail may not be precisely regulated.

[0021] Therefore, the arrival position of each mover controlled by the current control of the above control unit may not, strictly speaking, be the arrival position of the mover body, but rather the arrival position of the alignment reference point of the coil installed on the mover body.

[0022] Therefore, even if the installation position of the fixed jig installed on each mover is precisely regulated, the actual arrival position of the fixed jig may differ depending on the alignment reference point of the coil of the mover on which the fixed jig is installed.

[0023] In order to solve the above-described problem, the present invention sets a reference position of the mover on the rail, and the control unit controls the mover to stop at the reference position.

[0024] The above control unit can control the current applied to the electromagnet so that the mover stops at the reference position.

[0025] The above linear track system includes a detection unit that detects the stop position of the fixed jig of the mover stopped at the reference position.

[0026] The target position of the fixed jig is set on the above rail.

[0027] The above target position may include a first target position provided with a supply device for supplying a second part to the first part fixed to the above fixed jig.

[0028] The target position may include a second target position provided with an assembly device for assembling the second part to the first part fixed to the fixed jig.

[0029] Information on the deviation of the stop position with respect to the above reference position can correspond to the deviation of the alignment reference point of the fixed jig with respect to the alignment reference point of the coil.

[0030] The above control unit controls the mover to stop at an offset stop position that reflects the deviation information to the target position.

[0031] The above control unit can control the current applied to the electromagnet so that the mover stops at an offset stop position that reflects the deviation information to the target position.

[0032] Accordingly, when the mover reaches the offset stop position by current control of the control unit, the fixed jig can accurately reach the target position.

[0033] A reference recognition unit may be provided at the reference position of the above rail, and a stop recognition unit may be provided at the above fixed jig.

[0034] The above detection unit can generate information about the relative position of the stop recognition unit with respect to the reference recognition unit in the longitudinal direction of the rail.

[0035] In a partial embodiment, the detection unit can detect both the reference recognition unit and the stationary recognition unit outside the reference recognition unit and the stationary recognition unit.

[0036] In a specific embodiment, the reference recognition unit and the stationary recognition unit may include visual displays, and the detection unit may include an image acquisition device that captures the reference recognition unit and the stationary recognition unit in a direction perpendicular to the extension direction of the rail to generate video image information. For example, the image acquisition device may be a vision camera.

[0037] In a partial embodiment, the detection unit may be installed on one side of the reference recognition unit and the stationary recognition unit and detect a detection unit installed on the other side.

[0038] In a specific embodiment, the sensing unit may optically sense the sensing unit. For example, the sensing unit may be an optical encoder, and the sensing unit may be a plurality of slits arranged along the longitudinal direction of the rail.

[0039] In another specific embodiment, the sensing unit may electromagnetically sense the sensing unit. For example, the sensing unit may be a plurality of Hall sensors arranged along the length of the rail, and the sensing unit may be a magnet.

[0040] The above control unit can calculate the offset stop position based on the above information.

[0041] In a partial embodiment, the reference positions may be provided at multiple locations along the length of the rail.

[0042] The above mover stops at a plurality of reference positions, and the offset stop position can be determined by reflecting deviation information calculated from each of the plurality of reference positions.

[0043] In a partial embodiment, the rail may be provided with a plurality of movers each independently movable.

[0044] Each mover has a unique ID, and the control unit can store the deviation information of each mover in relation to the ID information.

[0045] The above deviation information is accumulated and stored, and the offset stop position of each mover can be determined by reflecting the accumulated and stored deviation information in relation to the ID information of each mover.

[0046] In a partial embodiment, the offset stop position may be determined by reflecting an average value of a plurality of deviation information.

[0047] In a partial embodiment, the offset stop position may be determined by reflecting deviation information that may be judged to be a detection error among a plurality of deviation information.

[0048] The above first component may be an electrode assembly.

[0049] The above second component may be a collector plate.

[0050] The above current collector plate may include a first current collector plate welded to a tab of a first electrode provided at an axial first end of the electrode assembly and / or a second current collector plate welded to a tab of a second electrode provided at an axial second end of the electrode assembly.

[0051] The above assembly device may be a welding device.

[0052] The assembly of the first and second parts may be performed by welding the current collector plate to the tab of the electrode of the electrode assembly.

[0053] The above welding device may include a laser generator.

[0054] The linear track system according to the present invention can further reduce the transport deviation, thereby enabling the assembly process of parts to be performed more precisely.

[0055] The linear track system according to the present invention can precisely perform the welding assembly process of the current collector plate to the electrode assembly even without precisely controlling the supply position of the current collector plate and the heating position for welding.

[0056] By applying the linear track system according to the present invention, the welding assembly process of the current collector plate for the electrode assembly can be performed precisely and quickly, thereby increasing the production speed.

[0057] In addition to the effects described above, specific effects of the present invention are described below while explaining specific details for carrying out the invention.

[0058] FIG. 1 is an exploded perspective view of an electrode assembly of a battery cell to which a linear track system of an embodiment according to the present invention can be applied.

[0059] Figure 2 is an exploded perspective view of the electrode assembly of Figure 1.

[0060] Figure 3 is a perspective view of an electrode assembly according to an embodiment of the present invention.

[0061] Fig. 4 is a perspective view showing a state in which a first collector plate is joined to the axial first end of the electrode assembly of Fig. 3.

[0062] Fig. 5 is a perspective view showing a state in which a second collector plate is joined to the axial second end of the electrode assembly of Fig. 3.

[0063] Figure 6 is a cross-sectional view of a completed battery cell.

[0064] Fig. 7 is a perspective view of a linear track system of an embodiment.

[0065] Fig. 8 is a plan view of the linear track system of Fig. 7.

[0066] Fig. 9 is a perspective view of the mover of the linear track system of Fig. 7, which has the first part removed.

[0067] Fig. 10 is a front view of the mover of Fig. 9.

[0068] Fig. 11 is a front view of a mover with different alignment reference points of the mover and coil of Fig. 10.

[0069] Fig. 12 is a front view showing a mover stopped at a reference position of a rail according to the first embodiment.

[0070] Fig. 13 is a rear perspective view showing a mover stopped at a reference position of a rail according to the second embodiment.

[0071] Fig. 14 is a rear view showing a mover stopped at a reference position of a rail according to the third embodiment.

[0072] Fig. 15 is a front view showing a mover that has reached a target position of a rail according to an embodiment.

[0073] [Explanation of symbols]

[0074] 10: Can (housing) 11: Side wall 12: End wall (first end wall) 13: Beading portion 14: Crimping portion 15: Rivet terminal (first electrode terminal) 16: Terminal gasket 19: Insulator 20: Electrode assembly (first part) 21: First electrode (positive electrode) 22: Second electrode (negative electrode) 23: Current collector (metal foil) 24: Active material 25: Holding portion 26: Non-conductive portion 27: Electrode tab (notched tab) 28: Separator 30: Positive collector plate (first collector plate) (second part) 31: Peripheral portion 32: Electrode connection portion 33: Central portion 34: Terminal connection portion 35: Bridge 36: Conductive portion 40: Negative collector plate (second collector plate) (second part) 41: Plate portion 42: Electrode joint 43: Pit part 44: Can joint 45: Leg part 46: Current carrying part 50: Cap (second end wall) 55: Gasket 60: Rail 61: Electromagnet 62: Control part SP, SP1, SP2, SP3, SP4, SP5, SP6: Reference position TP, TP1, TP2: Target position, first target position, second target position OP: Offset stop position 65: Reference recognition part (recognition mark) 70: Mover 71: Coil 71C: Alignment reference point 75: Fixed jig 75C: Alignment reference point 76: Stop recognition part (recognition mark, slit, magnet) 80: Detection part (image acquisition device, vision camera, encoder, hall sensor) RP: Stop position D: Deviation, deviation information 81: Feeder 82: Assembly device (welding device, laser generator) 90: Battery cell

[0075] The above-described objects, features, and advantages will be described in detail below with reference to the accompanying drawings, so that those skilled in the art can easily practice the technical idea of ​​the present invention. In describing the present invention, if it is determined that a detailed description of known technologies related to the present invention may unnecessarily obscure the gist of the present invention, a detailed description thereof will be omitted. Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numerals are used to indicate the same or similar components.

[0076] Although terms like "first" and "second" are used to describe various components, these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless otherwise specified, a "first" component may also be a "second" component.

[0077] Throughout the specification, unless otherwise specifically stated, each element may be singular or plural.

[0078] Hereinafter, the phrase "any configuration is placed on (or below)" a component or "on (or below)" a component may mean that any configuration is placed in contact with the upper surface (or lower surface) of said component, and that other configurations may be interposed between said component and any configuration placed on (or below) said component.

[0079] Additionally, when it is described that a component is "connected," "coupled," or "connected" to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be "interposed" between the components, or that each component may be "connected," "coupled," or "connected" through another component.

[0080] As used herein, singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as "consisting of" or "comprising" should not necessarily be construed to include all of the components or steps described in the specification, and should be construed to mean that some of the components or steps may not be included, or that additional components or steps may be included.

[0081] Throughout the specification, when we refer to "A and / or B", this means A, B, or A and B, unless otherwise stated, and when we refer to "C to D", this means C or more and D or less, unless otherwise stated.

[0082] In describing the embodiments, the term "axial direction" refers to the direction in which the axis forming the winding center of the jelly-roll-shaped electrode assembly, i.e., the core axis, extends. This can be understood as a concept encompassing both directions in which the axis extends. Therefore, in the specification, when the term "axial direction" is used without any specific configuration limitation, it can be understood as the direction in which the core axis extends.

[0083] In describing the embodiments, the term "radial direction" or "radial direction" refers to a direction toward or away from the axis. This can be understood as a concept that includes both directions toward or away from the axis.

[0084] In describing the embodiments, the circumferential direction or the circumferential direction refers to the direction surrounding the axis.

[0085] Based on the description of these directions, the width direction of the electrode assembly in the unfolded state corresponds to the axial direction of the jelly roll. The length direction of the electrode assembly in the unfolded state corresponds to the circumferential direction of the jelly roll. And the normal direction to the electrode surface in the unfolded state of the electrode assembly corresponds to the radial direction of the jelly roll.

[0086] Referring to FIGS. 1 to 6 below, the assembly process and structure of the electrode assembly and current collector of a cylindrical battery cell of an embodiment to which the linear track system according to the present invention can be applied will be described.

[0087] The battery cell of the embodiment may be, for example, a cylindrical battery cell having a form factor ratio (defined as the ratio of the diameter of the cylindrical battery cell divided by its height, i.e., the ratio of the diameter to the height) of greater than about 0.4.

[0088] Here, the form factor refers to a value indicating the diameter and height of a cylindrical battery cell. The cylindrical battery cell may be, for example, a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, a 46800 cell, or a 46950 cell. In the numerical value indicating the form factor, the first two numbers indicate the diameter of the cell, the next two numbers indicate the height of the cell, and the last number 0 indicates that the cross-section of the cell is circular.

[0089] The above battery cell may be a cylindrical battery cell having a roughly cylindrical shape, a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0090] According to another embodiment, a battery cell may be a cylindrical battery cell having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 75 mm, and a form factor ratio of 0.640.

[0091] According to another embodiment, a battery cell may be a cylindrical battery cell having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[0092] According to another embodiment, a battery cell may be a cylindrical battery cell having a generally cylindrical shape, a diameter of approximately 48 mm, a height of approximately 80 mm, and a form factor ratio of 0.600.

[0093] According to another embodiment, a battery cell may be a cylindrical battery cell having a generally cylindrical shape, a diameter of approximately 46 mm, a height of approximately 80 mm, and a form factor ratio of 0.575.

[0094] The present invention can of course also be applied to battery cells having a form factor ratio of approximately 0.4 or less, such as 18650 cells, 21700 cells, etc. For 18650 cells, the diameter is approximately 18 mm, the height is approximately 65 mm, and the form factor ratio is 0.277. For 21700 cells, the diameter is approximately 21 mm, the height is approximately 70 mm, and the form factor ratio is 0.300.

[0095] Referring to Fig. 6, the battery cell of the embodiment includes a housing (10) having a side wall (11) extending in the axial direction, an end wall (12) connected to an axial first end of the side wall (11), and an open end or opening provided at an axial second end of the side wall (11). The housing (10) may be a can (10) made of metal.

[0096] The above battery cell has a jelly-roll shaped electrode assembly (20) accommodated in the can (10).

[0097] The above electrode assembly (20) is prepared by preparing a first electrode (21), a second electrode (22), and a separator (28) having a predetermined width and extending in the longitudinal direction as shown in FIG. 1, and forming a laminated body by stacking the first electrode (21), the separator (28), the second electrode (22), and the separator (28) in that order as shown in FIG. 2, and winding this around a core shaft to produce a jelly-roll shape as shown in FIG. 3.

[0098] The above first electrode (21) may be an anode, and the above second electrode (22) may be a cathode. Of course, the opposite may also be the case.

[0099] The first electrode (21) and the second electrode (22) are manufactured in the form of a roll sheet that extends in the length direction with a predetermined width. The electrodes (21, 22) are manufactured in the form of forming an active material layer by applying an active material (24) to the surface of a metal foil constituting a current collector (23) and rolling it. The electrodes (21, 22) have a holding portion (25) region where the active material (24) is applied, and a non-coated portion (26) region where the active material (24) is not applied. The first electrode (21) has a non-coated portion (26) region at a first end of the current collector (23) in the width direction, and the second electrode (22) has a non-coated portion (26) region at a second end of the current collector (23) opposite the first end in the width direction.

[0100] Referring to FIGS. 1 and 2, the first electrode (21) and the second electrode (22) are laminated such that their uncoated portions (26) extend further outward in the width direction than the separator (28) at the first and second ends in the width direction of the electrode assembly (20), respectively. Referring to FIG. 3, the uncoated portion (26) of the first electrode (21) protrudes from the axial first end of the rolled jelly-roll, and the uncoated portion (26) of the second electrode (21) protrudes from the axial second end of the jelly-roll. The uncoated portion (26) itself functions as at least one electrode tab (27).

[0101] In the above-mentioned blank portion (26), notches can be formed at a predetermined interval to form flag-shaped notching tabs (27).

[0102] In the embodiment, the notching tabs (27) are exemplified as having an equilateral trapezoidal shape. However, their shapes may be various, such as a semicircle, a semi-ellipse, a triangle, a rectangle, a parallelogram, etc.

[0103] In addition, in the embodiment, a form in which the notching tabs (27) arranged along the longitudinal direction have the same width is exemplified. However, the width of the notching tabs may be gradually or stepwise widened from the core side to the outer periphery side.

[0104] In addition, as illustrated in FIGS. 1 and 2, the height of the notching tabs (27) gradually increases from the core side to the outer circumference side. However, differently from this, the height of these notching tabs may be implemented in a constant or gradually decreasing form.

[0105] In addition, in the embodiment, a structure is exemplified in which a notching tab (27) is deleted in a predetermined section of the core side end of the above-mentioned plain portion (26) and a predetermined section of the outer side end. However, it is obvious that, contrary to this, the notching tab may not be deleted in the core side end of the plain portion, the notching tab may not be deleted in the outer side end of the plain portion, or the notching tab may not be deleted in both sides.

[0106] In the jelly-roll type electrode assembly (20), the notched tab (27) can be folded and flattened in the radial direction as illustrated in FIG. 3. The notched tab (27) can be folded radially inward or outward. In the embodiment, a structure in which the notched tab (27) is folded radially inward is exemplified.

[0107] The above-mentioned notched tabs (27) may be pre-bent one by one during the process of forming a jelly-roll-shaped electrode assembly (20) by stacking and winding electrodes and separators, and then may be finally bent again after being wound in a jelly-roll shape. Alternatively, the above-mentioned notched tabs (27) may be bent all at once after stacking and winding electrodes and separators to form a jelly-roll-shaped electrode assembly.

[0108] The notching tabs (27) of the first electrode (21) and the notching tabs (27) of the second electrode (22), which are bent in the radial direction and overlapped in multiple numbers in the axial direction, can provide a plane that is substantially perpendicular to the axial direction at the axially opposite ends of the electrode assembly (20).

[0109] The first collector plate (30) and the second collector plate (40) can be joined to a substantially flat surface provided by bending the notched tabs (27) exposed at both axial ends of the electrode assembly (20), as shown in FIGS. 4 and 5.

[0110] Referring to Fig. 4, the first collector plate (30) includes a central portion (33) provided at a position corresponding to the core hollow portion of the electrode assembly (20), a peripheral portion (31) surrounding the central portion (33), and a bridge (35) extending radially to connect the central portion (33) and the peripheral portion (31). The bridge (35) functions as a conductive portion (36) that electrically connects the peripheral portion (31) and the central portion (33). An electrode connection portion (32) welded to a notched tab (27) of the first electrode (21) is provided in the peripheral portion (31).

[0111] Referring to Fig. 5, the second collector plate (40) includes a plate portion (41) laminated on the flat surface of the notched tabs (27) provided at the axial second end of the electrode assembly (20). The plate portion (41) may be an annular flat plate having a center hole corresponding to the core cavity of the electrode assembly (20). The surface of the plate portion (41) is penetratedly welded to the electrode tabs (27) of the second electrode (22) by a laser to form an electrode joint portion (42).

[0112] In addition, the second collector plate (40) includes a leg (45) that extends obliquely axially outward from the edge of the plate portion (41) toward the radial outer side. The leg portions (45) are exemplified as being provided in four pieces at 90-degree intervals along the circumferential direction, but the number and shape are not limited thereto.

[0113] Feet (43) are connected to the radially outer end of the leg portion (45). The feet (43) have an arc shape extending in the circumferential direction and are connected to the leg portion (45) at the center of the arc shape. The feet (43) are arranged at a position offset axially outwardly compared to the plate portion (41) and are arranged radially further outward than the plate portion (41). The feet (43) are exemplified as being provided in four numbers at 90-degree intervals along the circumferential direction to correspond to the leg portion (45), but the number and shape are not limited thereto.

[0114] In the embodiment, the first collector plate (30) is exemplified as a positive collector plate and the second collector plate (40) is a negative collector plate. Of course, the opposite may also be true.

[0115] The above first collector plate (30) may be made of aluminum, and the above second collector plate (40) may be made of copper. Of course, the opposite may also be true.

[0116] The above-mentioned collector plate (30, 40) can be manufactured by punching, trimming, piercing, or bending a metal sheet or metal plate.

[0117] Referring to Fig. 6, the electrode assembly (20) in which the collector plates (30, 40) are assembled is accommodated inside the can (10) through the opening of the can (10). Before inserting the electrode assembly (20) into the can (10), an insulator (19) can be laminated on the inner surface of the end wall (12). The insulator (19) electrically insulates the first collector plate (30) from the end wall (12).

[0118] The end wall (12) of the above can (10) may have a disc shape with a hole formed in the center, and the side wall (11) may have a circular tube shape surrounding the internal volume of the can (10).

[0119] A first electrode terminal (15) can be fitted into the hole. The first electrode terminal (15) can be fixed to the end wall (12) by being riveted while a terminal gasket (16) is interposed therebetween. The terminal gasket (16) is interposed between the first electrode terminal (15) and the end wall (12), thereby sealing the inside and outside of the can (10) to prevent leakage of the electrolyte, and electrically insulating the first electrode terminal (15) from the end wall (12).

[0120] However, the method of connecting the first electrode terminal (15) and the end wall (12) is not limited to this. For example, if there is a structure that can seal between the first electrode terminal (15) and the end wall (12) and electrically insulate the first electrode terminal (15) and the end wall (12), various other methods such as i) bolt-nut joint method, ii) glass seal method, or iii) chrome coating & PP-MAH thermal bonding method can also be applied.

[0121] The first electrode terminal (15) above may have a first polarity, and the can (10) may have a second polarity. That is, the end wall (12) of the can (10) and the side wall (11) connected thereto may both have a second polarity.

[0122] Accordingly, the battery cell may have both the first electrode terminal (15) and the second electrode terminal arranged at the axial end, i.e., the closed end, provided with the end wall (12). Then, the battery cell may have both the bus bar connected to the first electrode terminal (15) and the bus bar connected to the second electrode terminal positioned on one axial side (upper) of the battery cell.

[0123] In one example, the first electrode terminal (15) may be a positive terminal and the second electrode terminal may be a negative terminal. Of course, the opposite may also be true.

[0124] The electrode assembly (20) is accommodated in the can (10) in a state where the first collector plate (30) is aligned so as to face the end wall (12) of the can (10). At this time, an insulator (19) is interposed between the first collector plate (30) and the end wall (12) of the can (10) so as to electrically insulate the first collector plate (30) from the end wall (12).

[0125] And, the central portion (33) of the first collector plate (30) is joined to the first electrode terminal (15) fixed to the can (10) by resistance welding, ultrasonic welding, laser welding, or the like, to define a terminal connection portion (34). A welding device for welding the first collector plate (30) and the first electrode terminal (15) can approach the back surface (the surface facing the electrode assembly (20)) of the central portion (33) of the first collector plate (30) through the core hollow portion of the electrode assembly (20) from the open end of the can (10) to perform welding. Of course, in addition to this, the first collector plate (30) and the first electrode terminal (15) can also be joined by brazing or soldering. That is, various methods can be applied to the first collector plate (30) and the first electrode terminal (15) as long as they can be electrically connected and fixed to each other.

[0126] In a state where the electrode assembly (20) is accommodated inside the can (10), the electrode tab (27) of the second electrode (22) and the second current collector (40) can be arranged to face the open end of the side wall (11), i.e., the opening of the housing (10).

[0127] After accommodating the electrode assembly (20) in the can (10), the side wall (11) is concavely formed radially inwardly from the axial outer side of the electrode assembly (20) by plastic processing to form a beading portion (13). The beading portion (13) supports the electrode assembly (20) accommodated in the can (10) in the axial direction and also supports the inner surface of the edge of the cap (50) that covers the open end of the can (10) in the axial direction.

[0128] In a state where the beading portion (13) is formed, the pit portion (43) of the second collector plate (40) is located approximately above the beading portion (13). In addition, the pit portion (43) and the plate portion (41), which are arranged so as to have a height difference, are connected by a leg portion (45) that extends obliquely in the radial direction and the axial direction from the plate portion (41).

[0129] In this state, when the pit portion (43) is welded to the bead portion (13), the can (10) and the second collector plate (40) are electrically connected.

[0130] After the first collector plate (30) and the first electrode terminal (15) are joined and the second collector plate (40) and the beading portion (13) are joined, an electrolyte can be injected into the can (10). After the electrolyte is injected, the open end of the side wall (11) is covered by a cap (50) and sealed.

[0131] The battery cell (90) of the embodiment has a cap (50) that constitutes an end wall covering the open end of the can (10). The cap (50) is placed on the open end of the can (10) with a gasket (55) wrapped around its edge. Accordingly, the edge of the cap (50) is placed on the beading portion (13) to which the pit portion (43) is welded.

[0132] And the axial end of the side wall (11) is caulked from the axial outer side to the radial inner side of the cap (50) to form a crimping portion (14). The crimping portion (14) presses the edge of the outer surface of the cap (50) axially inward.

[0133] The gasket (55) surrounds the axial inner surface, the radial outer surface, and the axial outer surface of the edge of the cap (50) and is press-fitted between the cap (50) and the side wall (11), thereby sealing the can (10). The gasket (55) seals the gap between the crimping portion (14) and the cap (50), and electrically insulates the cap (50) from the side wall (11).

[0134] The battery cell (90) assembled in this manner has the end wall (12) of the can (10) and the first electrode terminal (15) both positioned on the upper surface with the cap (50) positioned on the bottom. Accordingly, all bus bars electrically connecting the battery cells (90) can be connected to the upper portion of the battery cells (90).

[0135] In assembling the above battery cell (90), the alignment and welding process of the electrode assembly (20) and the collector plates (30, 40) have a significant impact on the performance of the battery cell. Eccentricity of the electrode assembly (20) and the collector plates (30, 40), or non-welding or weak welding of the collector plates (30, 40) can cause an increase in internal resistance, internal short circuits, etc.

[0136] Referring to FIGS. 7 to 15 below, a linear track system capable of quickly and accurately performing a process of welding a first collector plate (30) and a second collector plate (40) to the electrode assembly (20) of FIG. 3 by aligning them with the electrode assembly (20) as shown in FIGS. 4 and 5 is described.

[0137] The linear track system includes a rail (60) extending along a predetermined transport path and a mover (70) transported along the rail (60). The rail (60) has a plurality of electromagnets (61) embedded along its length. The mover (70) has a coil (71) that electromagnetically interacts with the electromagnets (61).

[0138] The control unit (62) of the linear track system controls the current applied to the electromagnet (61) to move the mover (70) having the coil (71) built in. The mover (70) is guided along the extension direction of the rail (60) and is driven by the control unit (62). A plurality of movers (70) are installed on the rail (60) so that they can be independently controlled for movement.

[0139] The mover (70) is provided with a fixing jig (75) for holding a first component (20) to be transported by the mover (70). In an embodiment, the first component may be the jelly-roll-shaped electrode assembly (20) described above. The electrode assembly (20) is fixed to the fixing jig (75) so that its axial direction extends horizontally and is perpendicular to the transport direction of the rail (60), as illustrated. In an embodiment, the fixing jig (75) is provided with a gripper for holding a circumferential surface of the electrode assembly (20).

[0140] A coil (71) is built into the main body of the mover (70), and the fixing jig (75) is installed on the upper part of the main body. Accordingly, the coil (71) of the mover (70) is placed adjacent to the electromagnet (61) built into the rail (60) to electromagnetically interact with the electromagnet (61), and the electrode assembly (20) supported by the fixing jig (75) is positioned on the upper part of the rail (60). In addition, the main body of the mover (70) is installed with pulleys necessary to enable it to travel along the rail (60).

[0141] Around the rail (60), devices are installed to perform a predetermined process on the electrode assembly (20) supported by the fixed jig (75) of the mover (70) as the mover (70) is moved. Accordingly, in the linear track system, an assembly process is performed on the electrode assembly (20) that is moved along the rail (60).

[0142] The arrival position of each mover (70) is precisely controlled by the current control of the control unit (62). However, since the drive of the mover (70) is performed by the coil (71) interacting with the electromagnet (61), the arrival position of the mover (70) may be dominantly influenced by the position of the coil (71) built into the mover (70).

[0143] Accordingly, even if the installation positions of the coils (71) installed on each of the multiple movers (70) transported along the rail (60) are constant with respect to the main body of the mover (70), an error may occur in the actual position to which the main body of the mover (70) is transported. This is due to a difference in the alignment reference points of the coils (71) that electromagnetically interact with the electromagnet (61) of the rail (60).

[0144] For example, during the manufacturing process of the coil (71), a manufacturing deviation may occur in the coil (71) itself, and this manufacturing deviation appears as a deviation in the alignment reference point of the coil (71) that electromagnetically interacts with the electromagnet (61) of the rail (60). Therefore, even if the installation position of the coil (71) installed in each mover (70) is precisely regulated, it is difficult to expect the effect of precisely regulating the position of the alignment reference point of the coil (71) that results from electromagnetic interaction with the electromagnet (61) of the rail (60).

[0145] Therefore, the arrival position of each mover (70) controlled by the current control of the above control unit (62) is, strictly speaking, not the arrival position of the mover (70) body, but rather the arrival position of the alignment reference point of the coil (71) installed on the body of the mover (70).

[0146] For this reason, even if the installation position of the fixed jig (75) installed on each mover (70) is precisely regulated with respect to the main body of the mover (70), the actual arrival position of the fixed jig (75) may differ depending on the deviation of the alignment reference point (71C) of the coil (71) of the mover (70) on which the fixed jig (75) is installed.

[0147] In view of this, the present invention implements a procedure in the linear track system in which the control unit (62) controls the mover (70) running along the rail (60) to stop at a predetermined reference position (SP), detects whether the fixed jig (75) stopped at the reference position (SP) has reached the true reference position (SP) or has moved more or less than that, and checks whether the alignment reference point (75C) of the fixed jig (75) matches the alignment reference point (71C) of the coil (71), and if not, how much of a deviation there is.

[0148] According to the present invention, a reference position (SP) is set on the rail (60) at which the mover (70) is controlled to stop by the control unit (62). In addition, the linear track system provides a detection unit (80) that detects the actual stop position (RP) of the fixing jig (75) of the mover (70) that has stopped at the reference position (SP).

[0149] For example, as illustrated in FIG. 10, if the alignment reference point (71C) of the coil (71) of the mover (70) and the alignment reference point (75C) of the fixed jig (75) are coincident, then by the control of the control unit (62) that applies current to the electromagnet (61) to move the mover (70) to the reference position (SP), the alignment reference point (71C) of the coil (71) of the mover (70) almost exactly reaches the reference position (SP) and stops, and the fixed jig (75) whose alignment reference point (71C) of the coil (71) and its alignment reference point (75C) coincide with each other is also substantially exactly stopped at the reference position (SP).

[0150] However, as shown in Fig. 11, if there is a deviation (D) between the alignment reference point (71C) of the coil (71) of the mover (70) and the alignment reference point (75C) of the fixed jig (75), the fixed jig (75) of the mover (70) that has reached the reference position (SP) by the control unit (62) reaches a position that is deviated from the reference position (SP) by the deviation (D).

[0151] The linear track system of the embodiment provides a detection unit (80) for detecting the deviation (D). Referring to FIGS. 8 and 12, the detection unit (80) according to the first embodiment may be a vision camera (80). The image acquisition device (80) such as the vision camera captures a video image by photographing a reference recognition unit (65) capable of specifying a reference position (SP) of the rail (60) and a stop recognition unit (76) provided on the fixing jig (75) so as to identify an alignment reference point (75C) of the fixing jig (75) of the mover (70) while the mover (70) is stopped at the reference position (SP).

[0152] The above-mentioned reference recognition unit (65) and stationary recognition unit (76) may be recognition marks whose positions can be optically or visually specified. And the positions of these recognition marks can be specified by analysis of the video image. After specifying the two recognition marks (65, 76), the distance (D) between the two recognition marks in a direction parallel to the extension direction of the rail (60) can be calculated. The calculated distance can correspond to deviation information (D) between the alignment reference point (71C) of the coil (71) and the alignment reference point (75C) of the fixed jig (75).

[0153] In order to produce the above deviation information (D), software for analyzing the video image and calculating the distance may be built into the control unit (62).

[0154] Next, referring to FIG. 13, the detection unit (80) according to the second embodiment may be an encoder. According to the second embodiment, the encoder (80) may be a reference recognition unit (65) installed at the reference position (SP). In addition, the fixing jig (75) may be provided with a slit that can be read by the encoder (80). A plurality of slits spaced apart at regular intervals along the extension direction of the rail (60) may be a stop recognition unit (76) provided on the fixing jig (75).

[0155] The encoder (80) can optically read the slits (76) provided in the fixed jig (75) as the mover (70) is moved to the reference position (SP) and stops. For example, if 29 slits (76) are provided and the number of slits (76) read by the encoder (80) is 14 to 15, the deviation information (D) may be substantially 0.

[0156] In this way, the electrical signal generated when the encoder (80) reads the slits (76) is transmitted to the control unit (62), and the control unit (62) can check the actual stop position (RP) of the fixed jig (75) with respect to the reference position (SP) according to the number of the slits (76) read by the encoder (80), and can calculate deviation information (D) based on this.

[0157] Next, referring to FIG. 14, the detection unit (80) according to the third embodiment may be a Hall sensor. According to the third embodiment, the Hall sensor may be a reference recognition unit (65) installed at the reference position (SP). A plurality of the Hall sensors may be installed on both sides along the longitudinal direction of the rail (60) with the reference position (SP) as the center. In addition, a magnet that can be detected by the Hall sensor (80) may be provided at the fixing jig (75). The magnet (76) may be a stop recognition unit (76) installed at an alignment reference point (75C) of the fixing jig (75).

[0158] As the mover (70) is moved to the reference position (SP) and stops, the Hall sensor (80) of the rail (60) that the magnet (76) built into the fixed jig (75) of the mover (70) passes by recognizes the magnet (76) and generates a signal. For example, as shown in FIG. 14, if the magnet (76) passes by two of the five Hall sensors (80), two of the five Hall sensors (80) transmit signals to the control unit (62).

[0159] The above control unit (62) can detect the signal of the hall sensor (80) to confirm the actual stop position (RP) of the fixed jig (75). Accordingly, the control unit (62) can calculate deviation information (D) of the stop position (RP) with respect to the reference position (SP).

[0160] However, the implementation method of the reference recognition unit, the stationary recognition unit, and the detection unit of the present invention is not limited to the first to third embodiments, and if the above principle can be applied, it is obvious that various modifications are possible through known sensors.

[0161] The deviation information (D) of the stop position (RP) with respect to the above reference position (SP) can correspond to the deviation (D) of the alignment reference point (75C) of the fixed jig (75) with respect to the alignment reference point (71C) of the coil (71).

[0162] However, there is a possibility that there may be a slight difference between the actual deviation (D) and the deviation information (D) detected and calculated by the detection unit (80) due to an error occurring during the detection process of the detection unit (80).

[0163] According to a fourth embodiment of the present invention, in order to minimize the difference between the actual deviation (D) and the deviation information (D) calculated by the detection unit (80) and the control unit (62), a method is proposed in which the reference positions (SP) are provided at multiple locations along the longitudinal direction of the rail (60). Referring to FIGS. 7 and 8, in the first embodiment, the reference positions (SP) may be provided at six locations (SP1, SP2, SP3, SP4, SP5, SP6).

[0164] The above control unit (62) sequentially stops the mover (70) from moving to all of the reference positions (SP) of the plurality of locations.

[0165] A reference recognition unit (65) is provided for each of the above six reference positions, and a detection unit (80) is provided. In addition, the mover (70) that sequentially stops at the six reference positions is provided with a stop recognition unit (76) and a detection unit (80). Accordingly, the control unit (62) can acquire six deviation information (D) for one mover (70).

[0166] The above control unit (62) can minimize the error of the deviation information (D) by calculating the average value of the six deviation information (D). In addition, the control unit (62) can minimize the error of the deviation information (D) by calculating the average value after excluding the deviation information (D) whose value stands out more than other values ​​among the six deviation information (D).

[0167] By utilizing the waiting time of the mover (70) due to the time required for the supply and welding process of the second component, i.e., the collector plate (30, 40) to be described later, no additional time is required to acquire deviation information (D) from the reference positions of multiple locations.

[0168] According to a fifth embodiment of the present invention, in order to minimize the difference between the actual deviation (D) and the deviation information (D) calculated by the detection unit (80) and the control unit (62), a unique ID is assigned to each mover (70) independently controlled to move on the rail (60), and the control unit (62) stops each mover (70) at a reference position (SP) and stores the obtained deviation information (D) in association with the ID information. To this end, the control unit (62) may be equipped with a memory and a storage device for storing the information.

[0169] The above deviation information (D) can be accumulated and stored for each mover (70), and the control unit (62) can minimize the difference between the deviation information (D) and the actual deviation (D), for example, through the average value of the accumulated deviation information (D). In addition, the control unit (62) can further reduce errors in the deviation information (D) by calculating the average value after excluding particularly outstanding values ​​from the accumulated deviation information (D).

[0170] According to the linear track system of the present invention, a target position (TP) that the fixed jig (75) must accurately reach is set on the rail (60). The target position (TP) includes a first target position (TP1) provided with a supply device that supplies a collector plate (30, 40) to the electrode assembly (20) fixed to the fixed jig (75), and a second target position (TP2) provided with a welding device (82) that welds the collector plate (30, 40) supplied to the electrode assembly (20) to the electrode assembly (20).

[0171] For example, if the control unit (62) controls the mover (70) to reach the target position (TP), the actual arrival position of the fixed jig (75) may differ from the target position (TP) by the deviation (D).

[0172] According to the present invention, the control unit (62) calculates an offset stop position (OP) that reflects the deviation information (D) to the target position (TP), and controls the current applied to the electromagnet (61) so that the mover (70) reaches the offset stop position (OP) and stops.

[0173] Accordingly, when the mover (70) reaches the offset stop position (OP), the fixed jig (75) can actually reach the target position (TP) accurately. For example, referring to FIG. 15, each mover (70) may have different corresponding deviation information (D), and the control unit (62) can calculate the offset stop position (OP) of each mover (70) based on the deviation information (D) of each mover (70), and control each mover (70) to move to its respective offset stop position (OP).

[0174] In the above embodiment, it was explained by way of example that the stationary recognition unit is provided on the fixed jig. However, if the deviation between the fixed jig and the mover body is so small as to be negligible compared to the deviation between the fixed jig and the coil, the stationary recognition unit may be provided on the mover body. That is, in the above embodiment, the fact that the stationary recognition unit is provided on the fixed jig and the fact that the stationary recognition unit is provided on the mover body may be substantially the same concept.

[0175] It should be understood that the above-described embodiments are illustrative in all respects and not restrictive, and the scope of the present invention will be determined by the claims that follow, rather than by the detailed description set forth above. Furthermore, the meaning and scope of the claims that follow, as well as all possible modifications and variations derived from their equivalent concepts, should be construed as encompassing the scope of the present invention.

[0176] Although the present invention has been described with reference to the drawings exemplified above, it is to be understood that the present invention is not limited to the embodiments and drawings disclosed herein, and that various modifications may be made by those skilled in the art within the scope of the technical idea of ​​the present invention. Furthermore, even if the operational effects according to the configuration of the present invention have not been explicitly described while describing the embodiments of the present invention, it is natural that the effects predictable by the corresponding configuration should also be acknowledged.

Claims

1. A rail extended along a predetermined path; A mover that moves along the length of the rail by electromagnetic interaction with the rail; A fixing jig provided on the mover to fix the electrode assembly; Reference position of the mover provided on the above rail; Target position of the fixed jig provided on the above rail; A control unit that controls the above mover to stop at the reference position; and A detection unit for detecting the stop position of the fixed jig of the mover stopped at the above reference position; A linear track system in which the control unit controls the mover to stop at an offset stop position that reflects deviation information between the stop position of the fixed jig and the reference position at the target position.

2. In claim 1, the rail is equipped with an electromagnet along the longitudinal direction, The above mover has a coil that electromagnetically interacts with the electromagnet and is driven by a current applied to the electromagnet, A linear track system in which the control unit controls the current applied to the electromagnet so that the mover stops at the reference position, and controls the current applied to the electromagnet so that the mover stops at an offset stop position that reflects deviation information between the stop position of the fixed jig and the reference position at the target position.

3. A linear track system according to claim 1, wherein the target position includes a first target position provided with a collector plate supply unit that supplies a collector plate to an axial end of an electrode assembly fixed to the fixed jig.

4. A linear track system according to claim 3, wherein the target position includes a second target position provided with a laser welding section for welding the current collector plate to the electrode tab of the axial end of the electrode assembly fixed to the fixed jig.

5. In claim 1, a reference recognition unit is provided at the reference position of the rail, The above fixed jig is equipped with a stop recognition unit, A linear track system, wherein the above detection unit generates information regarding the relative position of the stop recognition unit with respect to the reference recognition unit in the longitudinal direction of the rail.

6. A linear track system according to claim 5, wherein the detection unit detects both the reference recognition unit and the stationary recognition unit from outside the reference recognition unit and the stationary recognition unit.

7. In claim 6, the reference recognition unit and the stationary recognition unit include visual displays, A linear track system, wherein the detection unit includes an image acquisition device that captures the reference recognition unit and the stationary recognition unit in a direction perpendicular to the extension direction of the rail to generate image information.

8. A linear track system according to claim 5, wherein the detection unit is installed on one side of the reference recognition unit and the stationary recognition unit and detects a detection unit installed on the other side.

9. A linear track system according to claim 8, wherein the sensing unit optically senses the sensing unit.

10. A linear track system according to claim 8, wherein the sensing unit electromagnetically senses the sensing unit.

11. A linear track system according to claim 5, wherein the control unit calculates the offset stop position based on the information.

12. A linear track system according to claim 1, wherein the reference positions are provided at multiple locations along the longitudinal direction of the rail.

13. In claim 12, the mover stops at a plurality of reference positions, A linear track system in which the above offset stop position is determined by reflecting deviation information calculated from each of a plurality of reference positions.

14. A linear track system according to claim 1, wherein a plurality of movers are installed on the rail so that they can move independently.

15. In claim 14, each mover has a unique ID, The above control unit stores the deviation information of each mover in relation to the ID information, in a linear track system.

16. A linear track system according to claim 15, wherein the deviation information is accumulated and stored.

17. A linear track system according to claim 16, wherein the offset stop position is determined by reflecting accumulated stored deviation information.

18. A linear track system according to claim 13 or 17, wherein the offset stop position is determined by reflecting an average value of a plurality of pieces of deviation information.

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