Restraint release device and restraint release method

Abstract

A restraint release device for a wound body 100 at which a laminate of a belt-like electrode plate and a belt-like separator is wound in the longitudinal direction and a winding-end end 100a is restrained by tape 112 comprises a cutting blade and a cutting blade drive mechanism that moves the cutting blade so as to form a cut line CL at the wound body 100. The cutting blade drive mechanism forms the cut line CL such that, in a view of the winding-end end 100a from the direction orthogonal to the axial direction A of the wound body 100, the cut line CL overlaps the winding-end end 100a and passes through a region R1 that is further to the side in the opposite direction of the winding direction B of the wound body 100 than the winding-end end 100a to overlap an axial-direction end 100b that is positioned in said region R1, and the entirety of the tape 112 is within the extension range R of the cut line CL in the axial direction A.

Description

Restraint release device and restraint release method

[0001] The present disclosure relates to a device and method for releasing a constraint on a wound body.

[0002] Conventionally, batteries have been known in which a wound assembly, in which positive and negative electrode plates are stacked with a separator sandwiched therebetween and wound, is housed in an outer can. Patent Document 1 describes a wound assembly disassembly device for such a wound assembly. This disassembly device unwinds the wound assembly, separates the positive electrode, negative electrode, and separator components, and winds each component individually. This allows the materials of each component to be efficiently separated, recovered, and reused.

[0003] Japanese Patent Application Laid-Open No. 2007-165136

[0004] In general, the winding end of a wound body is restrained by tape. However, Patent Document 1 does not mention a process for releasing the restraint of the wound body by the tape.

[0005] The present disclosure has been made in view of these circumstances, and one of its objectives is to provide a technique for releasing a wound body from being restrained by a tape.

[0006] One aspect of the present disclosure is a device for releasing a wound body in which a laminate of a strip-shaped electrode plate and a strip-shaped separator is wound in the longitudinal direction and the end of the wound body is restrained with tape. This device includes a cutting blade and a cutting blade drive mechanism that moves the cutting blade to form a cutting line on the wound body. When the end of the wound body is viewed from a direction perpendicular to the axial direction of the wound body, the cutting blade drive mechanism forms the cutting line so that the cutting line overlaps the end of the wound body, passes through a region on the opposite side of the end of the wound body from the winding direction, and overlaps with the axial end located in that region, and further so that the entire tape is contained within the extension range of the cutting line in the axial direction.

[0007] Another aspect of the present disclosure is a method for releasing a wound body in which a laminate of a strip-shaped electrode plate and a strip-shaped separator is wound in the longitudinal direction and the winding end is constrained with tape. This method includes forming a cutting line on the wound body with a cutting blade so that, when the winding end is viewed from a direction perpendicular to the axial direction of the wound body, the cutting line overlaps the winding end, passes through a region on the opposite side of the winding direction of the wound body from the winding end end, and overlaps with an axial end located in that region, and further so that the entire tape is contained within the extension range of the cutting line in the axial direction.

[0008] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure.

[0009] According to the present disclosure, a technique can be provided for releasing the constraint of a wound body by a tape.

[0010] Fig. 1(A) is a perspective view of a wound body. Fig. 1(B) is an exploded perspective view of the wound body. Fig. 1(B) is a perspective view of a constraint release device seen from above. Fig. 1(B) is an exploded perspective view of a cutting blade support unit. Fig. 1(B) is a perspective view of a portion of a constraint release device seen from below. Fig. 5(A) and Fig. 5(B) are bottom views of the constraint release device. Fig. 6(A) to Fig. 6(D) are views showing the operating status of the constraint release device. Fig. 6(B) is a plan view of a wound body on which a cutting line is formed. Fig. 6(B) is a plan view of a wound body according to a modified example.

[0011] The present disclosure will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0012] First, a description will be given of a wound body 100, which is the target of processing by the restraint release device 1 according to this embodiment. Fig. 1(A) is a perspective view of the wound body 100. Fig. 1(B) is an exploded perspective view of the wound body 100. In Fig. 1(B), the winding end of the innermost separator 106 is cut away to make it easier to understand the stacking state of each component. Also, in Fig. 1(B), the negative electrode current collector tab 108 and the positive electrode current collector tab 110 are not shown.

[0013] The wound body 100 has a structure in which a laminate 101 of a strip-shaped electrode plate and a strip-shaped separator 106 is wound in the longitudinal direction, and the winding end 100a is restrained by tape 112. In this embodiment, the laminate 101 is formed by stacking a first electrode plate 102, a separator 106, a second electrode plate 104, and a separator 106 in this order. The first electrode plate 102, the second electrode plate 104, and the separator 106 are each strip-shaped. The laminate 101 is wound in the longitudinal direction with the first electrode plate 102 on the outside. Therefore, the outermost peripheral surface of the wound body 100 is the first electrode plate 102.

[0014] As an example, one end of each of the first electrode plate 102, the second electrode plate 104, and the separator 106 is aligned with one another. The laminate 101 is then wound with this one end serving as the winding start end. The two separators 106 are the same length and are shorter than the first electrode plate 102. Therefore, the winding end ends 106a of the two separators 106 are located closer to the winding start end of the wound body 100 than the winding end end 102a of the first electrode plate 102. The second electrode plate 104 is also shorter than the separator 106. Therefore, the winding end end 104a of the second electrode plate 104 is located closer to the winding start end of the wound body 100 than the winding end ends 106a of the two separators 106. The first electrode plate 102 is longer than the second electrode plate 104 and the separator 106. Therefore, the winding end 102 a of the first electrode plate 102 corresponds to the winding end 100 a of the wound body 100 .

[0015] The first electrode plate 102 and the second electrode plate 104 have a structure in which an electrode active material layer is laminated on a current collector. In a typical lithium-ion secondary battery, the current collector is made of aluminum foil or the like for the positive electrode, and copper foil or the like for the negative electrode. The electrode active material layer can be formed by applying an electrode mixture to the surface of the current collector using a known coating device, followed by drying and rolling. The electrode mixture is obtained by kneading and uniformly dispersing materials such as an electrode active material, a binder, and a conductive material in a dispersion medium. In a typical lithium-ion secondary battery, the electrode active material is lithium cobalt oxide, lithium nickel oxide, lithium manganese oxide, nickel-cobalt-lithium aluminum oxide (NCA), nickel-manganese-cobalt-lithium cobalt oxide (NMC), lithium iron phosphate (LFP), lithium manganese iron phosphate (LMFP), lithium manganese phosphate (LMP), or the like for the positive electrode, and graphite or the like for the negative electrode. As an example, the first electrode plate 102 is a negative electrode plate, and the second electrode plate 104 is a positive electrode plate. There is no particular limitation on the number of electrode plates and separators 106 included in the wound body 100. For example, the wound body 100 may include either the first electrode plate 102 or the second electrode plate 104, and two separators 106.

[0016] The separator 106 is, for example, a microporous film made of polypropylene resin, polyethylene, or the like. A negative electrode current collector tab 108 is electrically connected to the negative electrode plate. The negative electrode current collector tab 108 may be formed as a portion of the current collector of the negative electrode plate. A positive electrode current collector tab 110 is electrically connected to the positive electrode plate. The positive electrode current collector tab 110 may be formed as a portion of the current collector of the positive electrode plate. The negative electrode current collector tab 108 protrudes in the axial direction A from one end of the wound body 100 in the axial direction A. The positive electrode current collector tab 110 protrudes in the axial direction A from the other end of the wound body 100 in the axial direction A. Note that the negative electrode current collector tab 108 and the positive electrode current collector tab 110 may protrude in the same direction from the same end. The axial direction A is the direction in which the axis of the winding center C extends or the width direction of each band. Hereinafter, the end of the wound body 100 in the axial direction A will be referred to as the axial end 100b as appropriate.

[0017] A tape 112 is attached to the outermost peripheral surface of the wound body 100 so as to straddle the winding end 100a in the winding direction B of the wound body 100. By fastening the winding end 100a with the tape 112, the wound body 100 is prevented from unwinding. As an example, one end side and the other end side of the wound body 100 in the axial direction A are each restrained by a tape 112. Furthermore, each tape 112 is wrapped around the entire circumference of the wound body 100. A known tape 112 can be used for the tape 112, and for example, the tape 112 has a structure in which an adhesive layer is provided on one surface of a resin base material.

[0018] The cylindrical wound body 100 bound by the tape 112 is housed in an outer can (not shown) together with an electrolyte (not shown), thereby completing a battery. The battery may be, for example, a rechargeable secondary battery such as a lithium ion battery, a nickel-metal hydride battery, or a nickel-cadmium battery.

[0019] Next, the constraint and release device 1 will be described. Figure 2 is a perspective view of the constraint and release device 1 as seen from above. The constraint and release device 1 includes a cutting blade 2 and a cutting blade drive mechanism 4. The cutting blade 2 has a hardness sufficient to cut at least the members located on the outermost surface of the wound body 100, in this embodiment the first electrode plate 102 and the tape 112. The constraint and release device 1 of this embodiment has a cutting blade 2 corresponding to each of the two tapes 112. The two cutting blades 2 are attached to the cutting blade drive mechanism 4 via cutting blade support units 6, respectively.

[0020] FIG. 3 is an exploded perspective view of the cutting blade support unit 6. Each cutting blade support unit 6 includes a cutting blade bracket 8, an angle adjustment plate 10, a fixing plate 12, a shaft 14, and a knob 16. The cutting blade bracket 8 is generally plate-shaped and long in one direction, with the angle adjustment plate 10 fixed to one main surface at one end in the longitudinal direction. In this embodiment, the cutting blade bracket 8 extends in the up-down or vertical direction, and the angle adjustment plate 10 is fixed to the lower end of the cutting blade bracket 8. The angle adjustment plate 10 has an elongated hole 10a extending in a direction intersecting the longitudinal direction of the cutting blade bracket 8. A fastening screw 18 is inserted into the elongated hole 10a. The angle adjustment plate 10 is fixed to the cutting blade bracket 8 by the fastening screw 18.

[0021] The angle adjustment plate 10 has a recess 10b on the surface facing away from the cutting blade bracket 8. The cutting blade 2 is fitted into the recess 10b. A fixing plate 12 is fixed to the angle adjustment plate 10 with a fastening screw 20. The fixing plate 12 is positioned so as to overlap the recess 10b and presses the cutting blade 2 fitted into the recess 10b against the angle adjustment plate 10. This fixes the cutting blade 2 to the angle adjustment plate 10. The cutting blade 2 is attached to the cutting blade bracket 8 via the angle adjustment plate 10 while being sandwiched between the fixing plate 12 and the angle adjustment plate 10. The position of the angle adjustment plate 10 can be changed in the extension direction of the elongated hole 10a relative to the cutting blade bracket 8 by loosening the fastening screw 18. This allows the angle of the cutting blade 2 relative to the wound body 100 to be adjusted.

[0022] A through-hole 8a extending from one main surface to the other main surface is provided at the upper end of the cutting blade bracket 8. A shaft 14 is inserted through the through-hole 8a. The tip of the shaft 14 protrudes from the other main surface of the angle adjustment plate 10, i.e., the main surface opposite the main surface to which the angle adjustment plate 10 is fixed. A knob 16 is attached to the base end of the shaft 14. The shaft 14 is cylindrical with an internal cavity and has a protrusion (not shown) on its outer circumferential surface. The protrusion is biased toward the outside of the shaft 14 by a biasing member (not shown), such as a spring, provided inside the shaft 14. The protrusion and the biasing member are connected to the knob 16 inside the shaft 14. By pulling the knob 16 in a direction away from the angle adjustment plate 10, the biasing force of the biasing member is released, and the protrusion can be retracted into the shaft 14.

[0023] The shaft 14 is inserted into a mounting hole (not shown) provided in the unit support part 30 of the cutting blade drive mechanism 4. A locking groove (not shown) is provided on the inner peripheral surface of the mounting hole. When the shaft 14 is inserted into the mounting hole, the protrusion fits into the locking groove. This secures the cutting blade support unit 6 to the cutting blade drive mechanism 4. Furthermore, by pulling the knob 16 to release the biasing force applied to the protrusion, the protrusion can be retracted into the shaft 14, and the cutting blade support unit 6 can be removed from the unit support part 30. In other words, the cutting blade support unit 6 can be easily attached to and detached from the cutting blade drive mechanism 4 without using tools.

[0024] The structure for fixing the cutting blade 2 to the cutting blade support unit 6, the structure for adjusting the angle of the cutting blade 2, and the structure for fixing the cutting blade support unit 6 to the cutting blade drive mechanism 4 are not limited to those described above, and other known structures may also be employed. Furthermore, the cutting blade 2 may be fixed directly to the cutting blade drive mechanism 4 without using the cutting blade support unit 6.

[0025] 2 , the cutting blade drive mechanism 4 forms a cutting line CL (see FIG. 7 ) on the wound body 100 by inserting the cutting blade 2 into the surface of the wound body 100 and moving it over the surface of the wound body 100. The cutting blade drive mechanism 4 includes, as an example, an advance / retreat direction drive unit 24, a cutting direction drive unit 26, a drive mechanism bracket 28, a unit support unit 30, and a wound body holder 32.

[0026] The advance / retract direction drive unit 24 advances and retracts the drive mechanism bracket 28 relative to the wound body 100. In this embodiment, the wound body 100 is disposed directly below the cutting blade drive mechanism 4, and the advance / retract direction drive unit 24 moves the drive mechanism bracket 28 up and down. The advance / retract direction drive unit 24 has a first drive unit 34 and a connecting plate 36. The first drive unit 34 has a motor and a power conversion mechanism. The motor generates rotational power. The power conversion mechanism converts the rotational power generated by the motor into linear power and transmits it to the connecting plate 36. The drive mechanism bracket 28 is fixed to the connecting plate 36. The first drive unit 34 moves the connecting plate 36 up and down, causing the drive mechanism bracket 28 fixed to the connecting plate 36 to advance and retract relative to the wound body 100.

[0027] The cutting direction drive unit 26 moves the cutting blade support unit 6 parallel to the surface of the wound body 100. In this embodiment, the cutting direction drive unit 26 moves the cutting blade support unit 6 horizontally. The cutting direction drive unit 26 has a second drive unit 38, a cam lever 40, and a guide rail 42 (see FIG. 4). The second drive unit 38 has a motor and a power conversion mechanism. The motor generates rotational power. The power conversion mechanism converts the rotational power generated by the motor into linear power and transmits it to the cam lever 40. The unit support unit 30 is connected to the cam lever 40. The unit support unit 30 is also connected to the guide rail 42.

[0028] The restraint and release device 1 of this embodiment has unit support parts 30 corresponding to each of the two cutting blade support units 6. Therefore, the cutting direction drive part 26 has cam levers 40 and guide rails 42 corresponding to each of the two unit support parts 30. The cam levers 40 and the guide rails 42 are combined one-to-one, and the two sets are arranged in the axial direction A of the wound body 100. In this embodiment, the two sets are arranged in the left-right direction. The second drive unit 38 moves the two cam levers 40 in the axial direction A of the wound body 100 in directions toward and away from each other.

[0029] The drive mechanism bracket 28 has an advance / retract direction extending portion 44, an intervening portion 46, and a cutting direction extending portion 48. The advance / retract direction extending portion 44 extends in the movement direction of the drive mechanism bracket 28, i.e., the up-down direction. The intervening portion 46 is fixed to the lower end of the advance / retract direction extending portion 44. The intervening portion 46 is generally plate-shaped and long in one direction, and is oriented so that its two main surfaces face the up-down direction. The intervening portion 46 extends in a direction intersecting the arrangement direction of the two cam levers 40, which in this embodiment is the front-to-rear direction of the restraint release device 1. The upper surface of one end of the intervening portion 46 is fixed to the lower end of the advance / retract direction extending portion 44. The second drive unit 38 is fixed to the lower surface of one end of the intervening portion 46. The cutting direction extending portion 48 is fixed to the lower surface of the other end of the intervening portion 46.

[0030] The cutting direction extending portion 48 is generally plate-shaped and long in one direction, and is oriented so that its two main surfaces face the vertical direction. The cutting direction extending portion 48 extends in the arrangement direction of the two cam levers 40. The upper surface of the central portion of the cutting direction extending portion 48 is fixed to the interposition portion 46. The guide rail 42 is fixed to the lower surface of the cutting direction extending portion 48. In addition, below the cutting direction extending portion 48, the wound body holding portion 32 is connected to the drive mechanism bracket 28.

[0031] Figure 4 is a perspective view of a portion of the restraint and release device 1 as viewed from below. Figures 5(A) and 5(B) are bottom views of the restraint and release device 1. The unit support part 30 has a base part 50, a support arm part 52, and a cam follower 54.

[0032] The base portion 50 is generally plate-shaped and long in one direction, and is oriented so that its two main surfaces face the vertical direction. The top surface of the base portion 50 is slidably connected to the guide rail 42. The support arm portion 52 is generally plate-shaped and long in one direction, and extends in the vertical direction. The upper end of the support arm portion 52 is fixed to a side surface at one end of the base portion 50. A mounting hole (not shown) is provided at the lower end of the support arm 52. The cutting blade support unit 6 is detachably fixed to the support arm portion 52 by inserting the shaft 14 into this mounting hole. A cam follower 54 is provided on the underside of the other end of the base portion 50. The cam follower 54 protrudes downward from the base portion 50. In this embodiment, the two unit support portions 30 have an axisymmetric shape with the left-right central axis of the restraint release device 1 as the axis of symmetry. Each unit support portion 30 is oriented so that the support arm portion 52 is positioned closer to the central axis than the cam follower 54 .

[0033] Each cam lever 40 is generally L-shaped and includes a first portion 40a and a second portion 40b. The first portion 40a extends in the direction in which the two cam levers 40 are aligned and is connected to the second drive unit 38. The second portion 40b extends from one end of the first portion 40a to pass below the guide rail 42. A base portion 50 extends between the second portion 40b and the guide rail 42. The second portion 40b is provided with an elongated hole 56 that is long in the direction in which the second portion 40b extends. A cam follower 54 is slidably inserted into the elongated hole 56. In this embodiment, the two cam levers 40 are symmetrical about the left-right central axis of the restraint release device 1. Each cam lever 40 is oriented such that the other end of the first portion 40a is located closer to the central axis than the second portion 40b.

[0034] The guide rails 42 extend obliquely in the direction in which the second drive unit 38 moves the cam levers 40, i.e., obliquely with respect to the axial direction A of the wound body 100. In this embodiment, each guide rail 42 combined with each cam lever 40 extends obliquely toward the rear of the restraint and release device 1 as it moves away from the left-right central axis of the restraint and release device 1.

[0035] As the two cam levers 40 open laterally from a position close to each other as shown in FIG. 5A to a position separated from each other as shown in FIG. 5B, the unit support parts 30 connected to each cam lever 40 by the cam followers 54 open laterally following the cam levers 40. At this time, each unit support part 30 moves along the guide rails 42. As a result, as the unit support parts 30 move away from each other, they are displaced toward the rear of the restraint and release device 1. The cam followers 54 of each unit support part 30 slide rearward along the elongated holes 56. Therefore, the cutting blades 2 supported by each unit support part 30 trace a trajectory that extends from a position near the center and front of the restraint and release device 1 to the left and right outer sides and toward the rear.

[0036] Returning to Figure 4, the wound body pressing unit 32 has a biasing rod 58 and a pressing unit 60. The biasing rod 58 extends in the movement direction of the drive mechanism bracket 28, which in this embodiment is the vertical direction, and its upper end is connected to the drive mechanism bracket 28. The biasing rod 58 is vertically displaceable relative to the drive mechanism bracket 28, and is biased downward by a biasing member such as a coil spring. A pressing unit 60 is fixed to the lower end of the biasing rod 58. A recess that follows the circumferential surface of the wound body 100 is provided on the lower surface of the pressing unit 60.

[0037] Next, the operation of the restraint and release device 1 will be described. Figures 6(A) to 6(D) are diagrams showing the operating conditions of the restraint and release device 1. First, as shown in Figure 6(A), the wound body 100 is placed directly below the cutting blade drive mechanism 4. The orientation of the wound body 100 is maintained by a fixture (not shown). The wound body 100 is set in the fixture with its orientation determined so that the winding end 100a faces the cutting blade drive mechanism 4. The orientation adjustment of the wound body 100 may be performed automatically by combining a rotation device (not shown) that rotates the wound body 100 in the winding direction B with a sensor (not shown) such as a camera that detects the winding end 100a, or may be performed manually by an operator.

[0038] Once the wound body 100 is set, as shown in FIG. 6(B), the cutting blade 2 and the wound body pressing part 32 are lowered toward the wound body 100 by the driving of the advance / retract direction driving part 24. Then, the pressing part 60 contacts the surface of the wound body 100 before the cutting blade 2. A part of the wound body 100 enters the recess of the pressing part 60.

[0039] Next, as shown in Figure 6 (C), the cutting blade 2 and the wound body holder 32 continue to move downward. If the wound body holder 32 attempts to move further downward while the pressing unit 60 is in contact with the wound body 100, the biasing rod 58 is pushed upward by the reaction force from the wound body 100 input to the pressing unit 60. This allows the wound body holder 32 to press the wound body 100 with an appropriate biasing force. Meanwhile, the cutting blade 2 further descends and is inserted into the surface of the wound body 100. The advancing / retracting direction driving unit 24 descends the cutting blade 2 so that the cutting blade 2 is inserted by the thickness of the first electrode plate 102 that forms the outermost surface of the wound body 100.

[0040] 6(D), with the cutting blade 2 inserted into the wound body 100, the cutting direction drive unit 26 drives the cutting blade 2 to move over the surface of the wound body 100. When viewed from the front-to-rear direction of the constraint and release device 1, the cutting blade 2 moves parallel to the axial direction A of the wound body 100. When viewed from the top-to-bottom direction of the constraint and release device 1, the cutting blade 2 moves obliquely to the axial direction A of the wound body 100. This cuts off a portion of the surface of the wound body 100. In this embodiment, two cutting blades 2 are associated with two tapes 112, respectively, and each cutting blade 2 passes through each tape 112.

[0041] The wound body 100 is pressed down by the wound body presser 32. This makes it possible to prevent the position of the wound body 100 from shifting when the cutting blade 2 moves over the surface of the wound body 100. In addition, in this embodiment, the two cutting blades 2 move in directions away from each other at both ends of the wound body 100, that is, toward the outside of the wound body 100. This causes forces that pull the both ends of the wound body 100 in opposite directions to each other. This makes it difficult for wrinkles to form on the surface of the wound body 100, and allows for accurate incisions to be made in the wound body 100. The two cutting blades 2 may also move from the outside of the wound body 100 toward the center.

[0042] FIG. 7 is a plan view of the wound body 100 on which cutting lines CL are formed. The two cutting lines CL formed by the cutting blade drive mechanism 4 driving the two cutting blades 2 each satisfy the following condition. That is, when the winding end 100a is viewed in a direction perpendicular to the axial direction A of the wound body 100, i.e., from the radial direction of the wound body 100, each cutting line CL overlaps the winding end 100a. In this embodiment, each cutting line CL overlaps the winding end 100a at point P1. Furthermore, each cutting line CL passes through region R1, which is located in the opposite direction to the winding direction B of the wound body 100 from the winding end end 100a, and overlaps with the axial end 100b located in region R1. In this embodiment, each cutting line CL overlaps with the axial end 100b at point P2. Furthermore, the entire tape 112 is contained within the extension range R2 of each cutting line CL in the axial direction A.

[0043] By satisfying the above-described conditions, the constraint of the wound body 100 by each tape 112 can be released. This allows for accurate separation and recovery of components from a wound body 100 in which a defect was detected during manufacturing or from a used wound body 100, allowing for reuse. Furthermore, the cutting line CL in this embodiment is a straight line extending obliquely with respect to the axial direction A from the winding end 100a to the axial end 100b. Therefore, the cutting line CL can be formed by simply moving the cutting blade 2. This prevents the structure of the cutting blade drive mechanism 4 from becoming complicated. Furthermore, the triangular cut pieces resulting from the formation of the cutting line CL, with the corners of the first electrode plate 102 and the vertices at points P1 and P2, are attached to the outermost first electrode plate 102 by the tape 112. This prevents the components of the wound body 100 from being separated, making it easier to separate the components.

[0044] The inclination angle of the cutting line CL with respect to the axial direction A can be set appropriately based on the designer's empirical knowledge or experiments, simulations, etc. The wound body 100 is cylindrical. Therefore, if the inclination angle is small, the cutting depth of the cutting blade 2 can be made shallow, but the degree of freedom in the insertion position of the cutting blade 2 relative to the wound body 100 is reduced. On the other hand, if the inclination angle is large, the degree of freedom in the insertion position of the cutting blade 2 relative to the wound body 100 is increased, but the cutting depth of the cutting blade 2 becomes deep. Because the first electrode plate 102 and the second electrode plate 104 contain metal foil, a deep cutting depth may shorten the life of the cutting blade 2. From this perspective, the inclination angle is preferably 10° to 30°, for example, 20°.

[0045] The amount of movement of the cutting blade 2 by the advance / retract direction drive unit 24 can be set in advance based on the designer's empirical knowledge or experiments or simulations, etc. The advance / retract direction drive unit 24 may also adjust the amount of movement of the cutting blade 2 in accordance with the measurement results of a sensor that measures the pressure input to the cutting blade 2.

[0046] Furthermore, the movement of the cutting blade 2 by the advance / retract direction drive unit 24 may be controlled as follows. That is, the first electrode plate 102 has higher rigidity than the separator 106. Therefore, when the first electrode plate 102 is located on the outermost peripheral surface of the wound body 100, the contour shape of the wound body 100 is likely to be maintained even if an external force is applied to the wound body 100 during the manufacturing process or transportation process of the wound body 100. In this case, the advance / retract direction drive unit 24 maintains the vertical position of the cutting blade 2 while the cutting direction drive unit 26 moves the cutting blade 2.

[0047] On the other hand, when the wound body 100 does not have the first electrode plate 102, or when a separator 106 with low rigidity is located on the outermost peripheral surface of the wound body 100, the surface of the wound body 100 is likely to be dented when an external force is applied to the wound body 100. In particular, the end of the wound body 100 in the axial direction A is likely to be dented. In this case, the advance / retract direction driving unit 24 gradually lowers the cutting blade 2 as the cutting blade 2 approaches the end of the wound body 100. This makes it possible to more reliably form the cutting line CL.

[0048] The embodiments of the present disclosure have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the invention defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, content that allows such design modifications is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Furthermore, any combination of components included in each embodiment is also valid as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched object.

[0049] FIG. 8 is a plan view of a wound body 100 according to a modified example. In the wound body 100 according to the modified example, the winding end 100a is restrained by only one tape 112. The tape 112 is a long strip in the axial direction A and extends over almost the entire wound body 100 in the axial direction A, excluding both ends. In this case, the restraint and release device 1 forms a single cutting line CL in the wound body 100 using a single cutting blade 2. Even if only one cutting line CL is formed, the cutting blade drive mechanism 4 can form a cutting line CL that satisfies the above-described conditions. In other words, when the winding end 100a is viewed from a direction perpendicular to the axial direction A of the wound body 100, the cutting line CL overlaps the winding end 100a at point P1, passes through a region R1 on the opposite side of the winding direction B from the winding end 100a, and overlaps the axial end 100b located in region R1 at point P2. Furthermore, the entire tape 112 is contained within the extension range R2 of the cutting line CL in the axial direction A. This allows the constraint of the wound body 100 by the tape 112 to be released.

[0050] The structure of the cutting blade driving mechanism 4 can be modified as appropriate as long as it is possible to form a cutting line CL that satisfies the above-mentioned conditions.

[0051] The embodiments may be specified by the following items: [First Item] A restraint and release device (1) for a wound body (100) in which a laminate (101) of strip-shaped electrode plates (102, 104) and a strip-shaped separator (106) is wound in the longitudinal direction and the winding end (100a) is restrained by a tape (112), the device comprising: a cutting blade (2); and a cutting blade drive mechanism (4) that moves the cutting blade (2) so as to form a cutting line (CL) in the wound body (100). When the winding end (100a) is viewed from a direction perpendicular to the axial direction (A) of the wound body (100), the cutting blade drive mechanism (4) forms the cutting line (CL) so that the cutting line (CL) overlaps with the winding end (100a), passes through a region (R1) on the opposite side of the winding direction (B) of the wound body (100) from the winding end (100a), overlaps with the axial end (100b) located in said region (R1), and further so that the entire tape (112) is contained within an extension range (R2) of the cutting line (CL) in the axial direction (A). [Item 2] The restraint and release device (1) of Item 1, wherein the cutting line (CL) is a straight line extending from the winding end (100a) to the axial end (100b). [Item 3] The restraint and release device (1) of item 1 or 2, wherein the wound body (100) is restrained by tapes (112) at one end side and the other end side in the axial direction (A), the restraint and release device (1) has cutting blades (2) corresponding to each of the two tapes (112), and the cutting blade drive mechanism (4) drives each cutting blade (2) to form two cutting lines (CL).[Item 4] A method for releasing a wound body (100) in which a laminate (101) of strip-shaped electrode plates (102, 104) and a strip-shaped separator (106) is wound in the longitudinal direction and the winding end (100a) is constrained by a tape (112), the method comprising: forming a cutting line (CL) in the wound body (100) with a cutting blade (2) so that, when the winding end (100a) is viewed from a direction perpendicular to the axial direction (A) of the wound body (100), the cutting line (CL) overlaps the winding end (100a), passes through a region (R1) on the opposite side of the winding direction (B) of the wound body (100) from the winding end end (100a), overlaps with an axial end (100b) located in the region (R1), and further the entire tape (112) is contained within an extension range (R2) of the cutting line (CL) in the axial direction (A). How to release restraint.

[0052] The present disclosure can be used for a device and a method for restraining and releasing a wound body.

[0053] 1 Restraint and release device, 2 Cutting blade, 4 Cutting blade drive mechanism, 100 Wound body, 100a Winding end, 100b Axial end, 101 Laminated body, 106 Separator, 112 Tape, A Axial direction, B Winding direction, CL Cutting line.

Claims

1. A device for releasing a wound body in which a laminate of a strip-shaped electrode plate and a strip-shaped separator is wound in the longitudinal direction and the end of the winding is restrained with tape, the device comprising: a cutting blade; and a cutting blade drive mechanism that moves the cutting blade to form a cutting line on the wound body, wherein when the end of the winding is viewed from a direction perpendicular to the axial direction of the wound body, the cutting blade drive mechanism forms the cutting line so that the cutting line overlaps the end of the winding, passes through an area on the opposite side of the end of the winding direction of the wound body from the end of the winding, and overlaps with the axial end located in that area, and further so that the entire tape is contained within the extension range of the cutting line in the axial direction.

2. The restraint release device according to claim 1, wherein the cutting line is a straight line extending from the winding end to the axial end.

3. A restraint and release device as claimed in claim 1 or 2, wherein the wound body is restrained by the tape at one end and the other end in the axial direction, the restraint and release device has a cutting blade corresponding to each of the two tapes, and the cutting blade drive mechanism drives each cutting blade to form the two cutting lines.

4. A method for releasing a wound body in which a laminate of a strip-shaped electrode plate and a strip-shaped separator is wound in the longitudinal direction and the end of the winding is restrained with tape, the method comprising forming a cutting line on the wound body with a cutting blade so that, when the end of the winding is viewed from a direction perpendicular to the axial direction of the wound body, the cutting line overlaps the end of the winding, passes through a region on the opposite side of the winding direction of the wound body from the end of the winding, and overlaps with the axial end located in that region, and further so that the entire tape is contained within the extension range of the cutting line in the axial direction.

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