JP6101328B2 - Winding device and method for manufacturing winding element - Google Patents

Description

  The present invention relates to a winding device for obtaining a winding element incorporated in, for example, a secondary battery or the like, and a manufacturing method of the winding element.

  For example, in a winding element used as a secondary battery such as a lithium ion battery, a positive electrode sheet coated with a positive electrode active material and a negative electrode sheet coated with a negative electrode active material are composed of two insulating materials. It is manufactured by being wound in a state of being overlapped via a separator. Moreover, a predetermined tab may be provided for each electrode sheet. Examples of the tab include a welding tab welded to an active material uncoated portion of the electrode sheet, and a cutting tab formed by intermittently cutting one end in the width direction of the electrode sheet.

  In a winding device that manufactures a winding element, each of the electrode sheets and separator supplied from a roll wound in a roll is transported to a rotatable core along a separate transport path. . Then, the wound core is wound in a state where the electrode sheet and the separator are overlapped with each other, and finally the terminal portion of the separator is fastened with a predetermined fixing tape to obtain a wound element (for example, a patent) Reference 1 etc.).

JP-A-11-265726

  By the way, in the obtained winding element, there is a demand for disposing a tab within a predetermined range along the circumferential direction of the winding element. Therefore, it is conceivable to set the tab arrangement position so that the tab is arranged at the center of the predetermined range.

  However, there may be variations in the thickness of the electrode sheet due to differences in the application thickness of the active material, etc., and the tabs may be disposed out of the predetermined range due to the variation in thickness. .

  For example, when the electrode sheet is relatively thick, the circumference of the electrode sheet or the like during winding increases more than usual, so the length of one circumference of the electrode sheet required for each circumference increases more than usual. End up. Therefore, as the winding progresses, each part along the longitudinal direction of the electrode sheet gradually shifts to the front side in the rotational direction of the winding core from the position where each part should be normally arranged. May be disposed out of the predetermined range toward the front side in the rotational direction.

  On the other hand, when the electrode sheet is relatively thin, the circumferential length of the electrode sheet or the like during winding is reduced more than usual, so that the length of one round of the electrode sheet required in each circumference is reduced. Therefore, as the winding progresses, each part of the electrode sheet gradually shifts to the rear side in the rotation direction of the winding core from the position where the electrode sheet should be normally arranged, and as a result, the tab rotates more than the predetermined range. There is a risk that it will be disposed rearward in the direction.

  In both cases, the amount of deviation along the rotation direction of the core between the position of each part along the longitudinal direction of the electrode sheet and the position where each part should normally be arranged is as the winding proceeds. It increases cumulatively and becomes the largest at the end of the electrode sheet. Therefore, in the tab provided on the terminal end side of the electrode sheet and disposed on the outer peripheral side of the winding element, a situation in which the tab is out of the predetermined range is particularly likely to occur.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a winding device and a winding element that can more reliably arrange a tab within a predetermined range along the circumferential direction of the winding element. It is to provide a manufacturing method.

  In the following, each means suitable for solving the above-described object will be described in terms of items. In addition, the effect specific to the means to respond | corresponds as needed is added.

Means 1. A strip-shaped electrode sheet having a predetermined tab and having an active material on the surface and a strip-shaped separator made of an insulating material are supplied from a predetermined supply mechanism to a rotatable core with its own central axis as a rotation axis. And a winding device that winds the electrode sheet and the separator while being stacked by rotating the winding core,
A circumferential length changing means capable of changing a length along the rotation direction of a portion of the winding core around which the electrode sheet and the separator are wound,
A thickness measuring means for measuring the thickness of the electrode sheet;
By controlling the circumferential length changing means based on the measurement result by the thickness measuring means, the winding sheet is wound along the rotation direction of the part where the electrode sheet and the separator are wound. Control means for controlling the length;
A winding device comprising:

  According to the above means 1, the length along the rotation direction of the portion of the core around which the electrode sheet or the like is wound based on the thickness of the electrode sheet measured by the control means (hereinafter referred to as the core core). (Referred to as perimeter).

  For example, when the measured thickness of the electrode sheet is relatively large, that is, as the winding proceeds, the rotation of the core is gradually performed from the position where each part along the longitudinal direction of the electrode sheet should be normally disposed In the case of shifting to the front side in the direction (hereinafter, simply referred to as “front side”), the control means makes the circumference of the winding core relatively small. As a result, at the beginning of winding, the respective portions of the electrode sheet are arranged on the rear side in the rotation direction of the winding core (hereinafter simply referred to as “rear side”) with respect to the position where the electrode sheet is normally arranged. And even if each part of the electrode sheet gradually shifts to the front side as the winding advances as much as the arrangement position shifts to the rear side in this way, the shift is absorbed. It becomes. As a result, a situation in which each of the parts of the electrode sheet is arranged to be largely deviated forward from the position where it should normally be arranged is less likely to occur.

  On the other hand, when the measured thickness of the electrode sheet is relatively small, that is, as the winding progresses, each part of the electrode sheet is gradually arranged on the rear side from the position where it should be normally arranged. In this case, the control means makes the circumference of the winding core relatively large. Thereby, at the beginning of winding, each part of the electrode sheet is disposed on the front side of the position where it should be normally disposed. And even if each part of the electrode sheet is gradually shifted to the rear side as the winding advances as much as the arrangement position is shifted to the front side in this way, the shift is absorbed. It becomes. As a result, it is less likely that the respective portions of the electrode sheet are arranged so as to be largely shifted rearward from the positions where they are normally arranged.

  As described above, according to the above-described means 1, it is possible to more reliably prevent each part of the electrode sheet from being greatly displaced from the position where it should be normally arranged. As a result, the tab provided on the electrode sheet can be more reliably arranged within a predetermined range along the circumferential direction of the winding element.

Mean 2. The thickness measuring means measures the thickness of the entire area of the electrode sheet scheduled to be wound, which is the electrode sheet for one element before winding, in the transport path of the electrode sheet upstream of the winding core. ,
The control means controls the circumference changing means based on a measurement result on the scheduled winding electrode sheet by the thickness measuring means, so that the winding core of the winding scheduled electrode sheet is wound. 2. The winding device according to claim 1, wherein the winding device is configured to control a length along the rotation direction of a portion where the electrode sheet and the separator are wound.

  According to the above means 2, the thickness of the electrode sheet before being wound is measured by the thickness measuring means. Therefore, the thickness of the electrode sheet can be measured more accurately, and the circumference of the core can be set more appropriately.

  Further, according to the above means 2, the thickness of the entire electrode sheet (scheduled winding electrode sheet) for one element before winding is measured in advance, and is measured in advance when the scheduled winding electrode sheet is wound. Based on the thickness, the circumference of the core is controlled. Therefore, it is possible to optimize the circumference of the winding core according to the thickness of the wound electrode sheet. As a result, the tab can be more reliably disposed within a predetermined range.

Means 3. The winding core includes two core pieces provided in a state extending in the direction of the rotation axis and arranged in a direction orthogonal to the rotation axis,
The circumference changing means moves one of the cores in the contact / separation direction with respect to the other core, so that the rotation direction of the portion of the core where the electrode sheet and the separator are wound is rotated. The winding device according to claim 1 or 2, wherein the winding device is configured to change the length along the length.

  According to the means 3, it is possible to change the circumference of the core with a relatively simple configuration. Therefore, the apparatus can be simplified, and the increase in cost can be suppressed.

  For example, the circumferential length changing means includes: a guide unit that holds one core piece in a state in which the core piece can be moved toward and away from the other core piece; and a drive unit that moves the one core piece along the contact and separation movement direction. By changing the distance between the two core pieces by moving one of the core pieces, the length along the rotation direction of the portion of the winding core around which the electrode sheet and the separator are wound is provided. You may change the height.

Means 4 . The thickness measuring means includes
A first length measuring roller that is hung on the outer periphery in a state in which the electrode sheet is bent, and rotates as the electrode sheet is conveyed;
A second length measuring roller disposed so as to sandwich the electrode sheet with the first length measuring roller, and rotating with the conveyance of the electrode sheet;
When the electrode sheet passes between the two length measuring rollers, the rotation amount of the first length measuring roller that contacts the inner peripheral surface of the electrode sheet and the second measurement that contacts the outer peripheral surface of the electrode sheet. The winding device according to any one of means 1 to 3 , wherein the winding device is configured to measure a thickness of the electrode sheet based on a difference from a rotation amount of the long roller.

According to the means 4 , the thickness of the electrode sheet being conveyed can be accurately measured by a relatively simple method.

Means 5 . Along the rotation direction of the portion around which the belt-like electrode sheet having a predetermined tab and having an active material on the surface and the belt-like separator made of an insulating material is wound, which is rotatable about its central axis as a rotation axis Manufacturing of a winding element for manufacturing a winding element formed by winding the electrode sheet and the separator around the winding core using a winding device including a winding core whose length can be changed A method,
A thickness measuring step for measuring the thickness of the electrode sheet;
A winding step of winding the electrode sheet and the separator,
In the winding step, based on the measurement result of the thickness measurement step, the length along the rotation direction of the portion of the core where the electrode sheet and the separator are wound is controlled. A method for manufacturing a wound element.

According to the means 5 , the same effect as that of the means 1 is achieved.

It is a perspective schematic diagram which shows schematic structure of a battery element. It is a plane schematic diagram of the positive electrode sheet for showing a positive electrode tab. It is a plane schematic diagram of the negative electrode sheet for showing a negative electrode tab. It is a schematic block diagram of a winding apparatus. It is a schematic block diagram of a winding part. It is an expansion schematic diagram of a winding core. It is a schematic diagram which shows a circumference change function etc. It is a graph which shows the relationship between the deviation | shift amount when the correction value a is variously changed, and the rotation speed of a core. It is a flowchart of a correction value determination process. It is a flowchart of a winding process. It is a schematic block diagram of the winding part when winding is started. It is a schematic block diagram of the winding part at the time of a separator being cut | disconnected. When the thickness of an electrode sheet is comparatively large, it is a schematic diagram for demonstrating the position of each site | part of an electrode sheet when not changing the circumference of a core. It is a schematic diagram for demonstrating the position of each part of an electrode sheet when not changing the circumference of a core in case the thickness of an electrode sheet is comparatively small. It is a figure which shows the table for tension determination in 2nd Embodiment.

Hereinafter, embodiments will be described with reference to the drawings.
[First Embodiment]
First, the structure of the lithium ion battery element as a winding element obtained by the winding apparatus will be described.

  As shown in FIG. 1, a lithium ion battery element 1 (hereinafter simply referred to as “battery element 1”) is a state in which a positive electrode sheet 4 and a negative electrode sheet 5 are overlapped via two separators 2 and 3. It is manufactured by being wound in. In the following, for convenience of explanation, the separators 2 and 3 and the electrode sheets 4 and 5 may be referred to as “various sheets 2 to 5”.

  The separators 2 and 3 each have a strip shape having the same width, and an insulator such as polypropylene (PP) is used to prevent the different electrode sheets 4 and 5 from contacting each other to cause a short circuit. It is configured.

  The electrode sheets 4 and 5 are made of thin metal sheets and have substantially the same width as the separators 2 and 3. Moreover, the active material is apply | coated to the front and back both surfaces of the electrode sheets 4 and 5. FIG. For example, an aluminum foil sheet is used as the positive electrode sheet 4, and a positive electrode active material (for example, lithium manganate particles) is applied to both the front and back surfaces at predetermined intervals. For example, a copper foil sheet is used for the negative electrode sheet 5, and a negative electrode active material (for example, activated carbon or the like) is applied to both the front and back surfaces at predetermined intervals. And ion exchange between the positive electrode sheet 4 and the negative electrode sheet 5 can be performed through the active material. More specifically, ions move from the positive electrode sheet 4 side to the negative electrode sheet 5 side during charging, and ions move from the negative electrode sheet 5 side to the positive electrode sheet 4 side during discharging.

  In addition, in the present embodiment, the lengths of the electrode sheets 4 and 5 constituting each battery element 1 are set to predetermined predetermined values. In the present embodiment, the length of the positive electrode sheet 4 for one element is, for example, 13000 mm, and the length of the negative electrode sheet 5 for one element is more reliably determined by the negative electrode sheet 5. In order to cover, the length is slightly larger (for example, 13500 mm) than the length of the positive electrode sheet 4 for one element.

  In addition, as shown in FIG. 2, the active material non-applied portion 4b in the positive electrode sheet 4 (in FIGS. 2 and 3, the active material-applied portion has a dotted pattern) is provided as a positive tab. The electrode tab 4a is welded, and a protective tape 7 for protecting the positive electrode tab 4a is attached. Further, as shown in FIG. 3, a negative electrode tab 5a as a tab is welded to the active material uncoated portion 5b in the negative electrode sheet 5, and a protective tape 7 for protecting the negative electrode tab 5a is provided. It is affixed. A plurality of positive electrode tabs 4 a extend from one edge in the width direction of the positive electrode sheet 4, and a plurality of negative electrode tabs 5 a extend from the other edge in the width direction of the negative electrode sheet 5. .

  Further, in the battery element 1 according to the present embodiment, the outer peripheral shape in the cross section perpendicular to the axis is a rotationally symmetric shape such as an ellipse or an ellipse. And the positive electrode tab 4a and the negative electrode tab 5a are comprised so that it may be arrange | positioned in the predetermined range along the circumferential direction of the battery element 1, respectively. In the present embodiment, in the ideal state, the positive electrode tabs 4a are arranged in two rows at one end portion of the battery element 1, and the negative electrode tabs 5a are arranged in two rows at the other end portion of the battery element 1. (See FIG. 1).

  In obtaining a lithium ion battery, the wound battery element 1 is disposed in a battery container (case) (not shown) that is made of metal and has a cylindrical shape, and the positive electrode tab 4a and the negative electrode tab 5a are gathered together. It is done. Then, the combined positive electrode tab 4a is connected to a positive terminal component (not shown), and the negative electrode tab 5a is also connected to a negative terminal component (not shown). A lithium ion battery can be obtained by being provided so as to close both ends of the container.

  Next, the winding device 10 for manufacturing the battery element 1 will be described. As shown in FIG. 4, the winding device 10 includes a winding unit 11 for winding various sheets 2 to 5, and a positive electrode sheet supply mechanism 31 for supplying the positive electrode sheet 4 to the winding unit 11. A negative electrode sheet supply mechanism 41 for supplying the negative electrode sheet 5 to the winding unit 11; separator supply mechanisms 51 and 61 for supplying the separators 2 and 3 to the winding unit 11; The control device 81 is provided. Various mechanisms in the winding device 10 such as the winding unit 11 and the supply mechanisms 31, 41, 51, 61 are controlled by a control device 81.

  The positive electrode sheet supply mechanism 31 includes a positive electrode sheet original fabric 32 in which the positive electrode sheet 4 is wound in a roll shape. The positive electrode sheet original fabric 32 is supported so as to be freely rotatable, and the positive electrode sheet 4 is appropriately pulled out from here.

  In addition, the thickness of the positive electrode sheet 4 constituting the positive electrode sheet raw fabric 32 may be different for each lot of the positive electrode sheet raw fabric 32 because the application thickness of the active material is different. Moreover, also in the positive electrode sheet 4 which comprises the one positive electrode sheet original fabric 32, thickness may differ in each site | part. The same applies to the negative electrode sheet 5.

  The positive electrode sheet supply mechanism 31 includes a sheet insertion mechanism 71, a sheet cutting cutter 72, a tension applying mechanism 73, a buffer mechanism 75, and a thickness measuring mechanism 77 as a thickness measuring unit.

  The sheet insertion mechanism 71 supplies the positive electrode sheet 4 to the winding unit 11, and approaches the winding unit 11 along the conveyance path of the positive electrode sheet 4, and is separated from the winding unit 11. It is configured to be movable to a separated position. The sheet insertion mechanism 71 includes a pair of chucks 71 a and 71 b that can grip the positive electrode sheet 4. The chucks 71a and 71b are configured to be opened and closed by driving means (not shown). When the positive electrode sheet 4 is supplied to the winding unit 11, the sheet insertion mechanism 71 approaches the winding unit 11 after the positive electrode sheet 4 is gripped by the chucks 71 a and 71 b. ing.

  The sheet cutting cutter 72 is for cutting the positive electrode sheet 4 and includes a pair of blade portions 72 a and 72 b positioned on both the front and back sides of the positive electrode sheet 4. The sheet cutting cutter 72 is movable between a sheet cutting position where the pair of blade portions 72 a and 72 b sandwich the positive electrode sheet 4 and a retreat position where the positive electrode sheet 4 is retreated out of the conveyance path. It is configured.

  The positive electrode sheet 4 is cut while the positive electrode sheet 4 is held by the chucks 71a and 71b. Further, when the sheet insertion mechanism 71 moves closer to the winding part 11 side to supply the positive electrode sheet 4 to the winding part 11, the pair of blade parts 72 a and 72 b respectively transport the positive electrode sheet 4. By moving away from the path, the movement of the sheet insertion mechanism 71 is not hindered.

  The tension applying mechanism 73 includes a pair of rollers 73a and 73b and a dancer roller 73c provided so as to be swingable between the rollers 73a and 73b. The dancer roller 73c is operated by a predetermined servo motor (not shown) whose torque is controlled, and is configured such that the tension applied to the positive electrode sheet 4 can be changed by the control device 81 controlling the servo motor. ing. The dancer roller 73 c also serves to prevent loosening of the positive electrode sheet 4 by applying tension to the positive electrode sheet 4.

  The buffer mechanism 75 includes a pair of driven rollers 75a and 75b, and an elevating roller 75c provided between the rollers 75a and 75b so as to be vertically displaceable. By providing the buffer mechanism 75, the positive electrode sheet 4 having a length constituting one battery element can be stored between the sheet cutting cutter 72 and the thickness measuring mechanism 77.

  The thickness measuring mechanism 77 includes a pair of rollers 77a and 77b, a first length measuring roller 77c, and a second length measuring roller 77d. On the outer periphery of the first length measuring roller 77c, the positive electrode sheet 4 positioned between both rollers 77a and 77b is folded and bent. The second length measuring roller 77d is disposed so as to sandwich the folded portion of the positive electrode sheet 4 with the first length measuring roller 77c.

  The length measuring rollers 77c and 77d are driven rollers that have the same diameter and can freely rotate, and rotate as the positive electrode sheet 4 is conveyed. The rotation amounts of both length measuring rollers 77c and 77d can be grasped by an encoder (not shown), and information related to the rotation amounts of both length measuring rollers 77c and 77d is input to the control device 81 from the encoder. It has become.

  Since the positional relationship between the two length measuring rollers 77c and 77d and the positive electrode sheet 4 is set as described above, when the positive electrode sheet 4 passes between the two length measuring rollers 77c and 77d, The amount of rotation of the first length measuring roller 77c that contacts the inner peripheral surface (bent inner surface) of the electrode sheet 4 and the amount of rotation of the second length measuring roller 77d that contacts the outer peripheral surface (bent outer surface) of the positive electrode sheet 4 There will be a difference. The difference in the amount of rotation is larger as the positive electrode sheet 4 is thicker and smaller as the positive electrode sheet 4 is thinner.

  The negative electrode sheet supply mechanism 41 includes a negative electrode sheet original fabric 42 in which the negative electrode sheet 5 is wound in a roll shape on the most upstream side. The negative electrode sheet original fabric 42 is rotatably supported, and the negative electrode sheet 5 is appropriately pulled out from here.

  Further, in the middle of the conveyance path of the negative electrode sheet 5 from the negative electrode sheet original 42 to the winding part 11, as in the conveyance path of the positive electrode sheet 4, a sheet insertion mechanism 71, a sheet cutting cutter 72, tensioning is applied. A mechanism 73, a buffer mechanism 75, a thickness measuring mechanism 77, and the like are provided. Since these various configurations are the same as those provided in the conveyance path of the positive electrode sheet 4, detailed description thereof is omitted.

  On the other hand, the separator supply mechanisms 51 and 61 are provided with original separators 52 and 62 in which the separators 2 and 3 are wound in a roll shape, respectively. The separator webs 52 and 62 are supported so as to be freely rotatable, and the separators 2 and 3 are appropriately pulled out therefrom.

  Further, a tension applying mechanism 73 is provided in the middle of the transport path of the separators 2 and 3, similarly to the transport path of the electrode sheets 4 and 5. Since the various configurations of the tension applying mechanism 73 are the same as those provided in the conveyance path of the electrode sheets 4 and 5, detailed description thereof will be omitted.

  The tension applying mechanism 73 of each of the supply mechanisms 31, 41, 51, 61 is configured to be able to change the tension applied to the various sheets 2 to 5. A constant tension is always applied to the sheets 2 to 5.

  Further, various guide rollers (reference numerals omitted) for guiding the various sheets 2 to 5 such as a pair of guide rollers 78 a and 78 b that collectively collect the various sheets 2 to 5 are provided in the middle of the supply paths of the various sheets 2 to 5. Is provided.

  Next, the configuration of the winding unit 11 will be described. As shown in FIG. 5, the winding unit 11 includes a turret 12 composed of two opposing disk-like tables rotatably provided by a driving mechanism (not shown), and an interval of 180 ° in the rotation direction of the turret 12. And two support rollers 15a and 15b provided at positions shifted by about 90 ° in the rotation direction of the turret 12 with respect to the cores 13 and 14, respectively, and a separator cutter. 16, a presser roller 17 for pressing various sheets 2 to 5 after winding, and a tape applying mechanism 18 for applying a predetermined fixing tape.

  The winding cores 13 and 14 are for winding the various sheets 2 to 5 on the outer peripheral side of the winding cores 13 and 14, respectively, and are configured to be rotatable about their own central axis as a rotation axis by a driving mechanism (not shown). The amount of rotation of the winding cores 13 and 14 can be grasped by an encoder (not shown), and information regarding the amount of rotation is input to the control device 81 from the encoder.

  Further, the winding cores 13 and 14 are provided so as to be capable of appearing and retracting with respect to one table constituting the turret 12 along the axial direction of the turret 12 (the depth direction in FIG. 5). When the cores 13 and 14 protrude from the one table, the leading ends thereof are inserted into receiving holes formed in the other table, and can be rotated by both tables. It has come to be supported.

  Furthermore, the winding cores 13 and 14 are configured to be capable of turning between the winding position P1 and the removal position P2 when the turret 12 rotates.

  The winding position P1 is a position where the various sheets 2 to 5 are wound around the winding cores 13 and 14, and the various sheets 2 to 2 are respectively supplied from the supply mechanisms 31, 41, 51 and 61 to the winding position P1. 5 will be supplied.

  The removal position P <b> 2 is a position for removing the various sheets 2 to 5 after winding, that is, the battery element 1. In the periphery of the removal position P2, a removal device (not shown) for removing the battery element 1 from the winding cores 13 and 14 is provided.

  The support rollers 15a and 15b are for hooking and supporting the various sheets 2 to 5 between the winding cores 13 and 14 moved to the removal position P2 and the supply mechanisms 31, 41, 51 and 61.

  The separator cutter 16 is disposed in the vicinity of the winding position P1, and is a cutting position that approaches the turret 12 and cuts the separators 2 and 3, and a retreat position that is separated from the turret 12 and does not hinder the movement of the winding cores 13 and 14. It is possible to move between.

  The presser roller 17 is disposed in the vicinity of the removal position P2, and is located near the turret 12 and presses the various sheets 2 to 5, and a retreat position that is separated from the turret 12 and does not hinder the movement of the winding cores 13 and 14. It is configured to be movable between.

  The tape applying mechanism 18 is disposed in the vicinity of the removal position P2 and has a function of approaching the turret 12 and attaching a predetermined fixing tape to the end portions of the separators 2 and 3 at the end of winding. Note that a serial number of the battery element 1 to be attached is preliminarily attached to the fixing tape by printing or the like.

  Next, a more detailed configuration of the winding cores 13 and 14 in the present embodiment and a configuration of a circumferential length changing mechanism 91 as a circumferential length changing means provided corresponding to each of the winding cores 13 and 14 will be described.

  As shown in FIG. 6, the core 13 (14) includes a pair of core pieces 13 a and 13 b (14 a and 14 b) that extend along the direction of the rotation axis (the depth direction in FIG. 6). Each of the core pieces 13a and 13b (14a and 14b) is flat and is provided in a state of being arranged in a direction orthogonal to the rotation axis, and a gap 13c is provided between the core pieces 13a and 13b (14a and 14b). (14c) is formed. Moreover, the site | part located on the opposite side to the said clearance gap 13c (14c) among the outer peripheral surfaces of core piece 13a, 13b (14a, 14b) is made into the semicircle shape of a cross section with a diameter of R (mm).

  In addition, of the outer peripheral surfaces of the core pieces 13a and 13b (14a and 14b), the surfaces connecting the edge of the surface forming the gap 13c (14c) to the edge of the semicircular portion are flat. Yes. In the present embodiment, the core L is changed by changing the size L of the gap 13c (14c) and the width W of the flat portion of the core 13 (14) by the circumferential length changing mechanism 91 described below. 13 (14) is configured such that the length along the rotational direction of the portion around which the various sheets 2 to 5 are wound (hereinafter referred to as the circumferential length of the core 13 (14)) can be changed. In addition, the size L of the gaps 13c and 14c is usually such that when the battery element 1 is obtained by winding the ideal electrode sheets 4 and 5 having no variation in thickness, The tabs 4a and 5a are arranged in a predetermined range along the circumferential direction of the battery element 1 (in this embodiment, they are arranged in two rows, respectively).

  As shown in FIG. 7, the circumferential length changing mechanism 91 in the present embodiment is provided mainly corresponding to one core piece 13a (14a). The circumference changing mechanism 91 is controlled by the control device 81 and includes a guide portion 92 and a drive portion 93.

  The guide part 92 holds one core piece 13a (14a) in a state in which it can move toward and away from the other core piece 13b (14b). The guide portion 92 has a rail portion 92a extending in a direction orthogonal to the rotation axis of the winding core 13 (14) and an end portion of the one core piece 13a (14a) fixed to the rail portion 92a in the longitudinal direction. And a slide portion 92b mounted so as to be relatively movable along. The slide portion 92b moves relative to the rail portion 92a, and the one core piece 13a moves toward and away from the other core piece 13b (14b), thereby increasing or reducing the size L of the gap 13c (14c). As a result, the circumference of the core 13 (14) can be changed. In the present embodiment, a force in a direction to reduce the size L of the gap 13c (14c) is always urged against the one core piece 13a (14a) by a predetermined urging member (not shown). It is in a state.

  The drive part 93 has a connecting part 93a having one end fixed to one core piece 13a (14a), a roller part 93b attached to the other end of the connecting part 93a, and the axial direction of the winding core 13 (14). And a reciprocating movement portion 93c that can reciprocate along. An inclined portion 93d that is inclined with respect to the moving direction of the slide portion 92b is provided at the tip of the reciprocating portion 93c, and the roller portion 93b is applied to the inclined portion 93d by the urging force from the urging member. The outer peripheral surface is pressed.

  The size L of the gap 13c (14c) can be adjusted by reciprocating the reciprocating portion 93c. More specifically, when the reciprocating portion 93c is moved forward, a force in a direction against the urging force is applied to the roller portion 93b from the inclined portion 93d. As a result, a force is applied from the roller portion 93b to the one core piece 13a (14a) in the direction of enlarging the size L of the gap 13c (14c) via the connecting portion 93a, and the one core piece 13a (14a) becomes the gap 13c. It moves in the direction of enlarging the size L of (14c). When the reciprocating portion 93c is stopped, the roller portion 93b is pressed against the inclined portion 93d by the urging force, and the one core piece 13a (14a) is stopped. As a result, the size L of the gap 13c (14c) is maintained in an enlarged state.

  On the other hand, by reciprocating the reciprocating movement part 93c, the one core piece 13a (14a) moves in the direction of reducing the size L of the gap 13 (14c) by the biasing force. When the reciprocating portion 93c is stopped, the roller portion 93b is pressed against the inclined portion 93d by the urging force. As a result, one core piece 13a (14a) is stopped and the size L of the gap 13c (14c) is maintained in a reduced state.

  Returning to FIG. 5, the control device 81 includes a CPU as a calculation means, a ROM that stores various programs, a RAM that temporarily stores various data such as calculation data and input / output data, and a hard disk that stores calculation data and the like for a long time. As described above, the operation of the winding unit 11 and the supply mechanisms 31, 41, 51, 61 is controlled.

  The control device 81 controls the supply start / supply stop timing of the electrode sheets 4 and 5 to the winding unit 11, the rotation of the winding cores 13 and 14, the operation of the circumferential length changing mechanism 91, and the like. For example, the control device 81 is configured so that information relating to the feed amounts of the electrode sheets 4 and 5 is input from an encoder (not shown), and when the feed amounts of the electrode sheets 4 and 5 reach predetermined values, the electrodes The feeding (supply) of the sheets 4 and 5 is stopped.

  By the way, when the thickness of the wound electrode sheets 4 and 5 is larger or smaller than the reference value, the obtained battery element 1 may be displaced in the positions of the tabs 4a and 5a. Therefore, the control device 81 changes the peripheral length of the cores 13 and 14 by controlling the peripheral length changing mechanism 91 based on the thickness of the electrode sheets 4 and 5 in order to suppress the displacement of the tabs 4a and 5a. To do.

  More specifically, the control device 81 determines the distance between the length measuring rollers 77c and 77d during the period from the start of feeding of the electrode sheets 4 and 5 to the stop of feeding based on the input information regarding the rotation amount of the length measuring rollers 77c and 77d. The thickness of the whole area along the longitudinal direction in the electrode sheet 4 and 5 for one element which passes through is measured. The electrode sheets 4 and 5 for one element passing between the length measuring rollers 77c and 77d are wound up at the next winding. The control device 81 stores in advance a table showing a correspondence relationship between the difference in rotation amount between the length measuring rollers 77c and 77d and the thickness of the electrode sheets 4 and 5, and by referring to the table, The thickness of the electrode sheets 4 and 5 passing between the length measuring rollers 77c and 77d is obtained.

  Moreover, the control apparatus 81 obtains the average value of the thickness of each electrode sheet 4 and 5 for one element based on the measured thickness. Further, the control device 81 obtains a value x (mm) obtained by subtracting the reference value (ideal value) of the thickness of the positive electrode sheet 4 from the average value of the thicknesses of the obtained positive electrode sheet 4, and the obtained negative electrode. A value y (mm) obtained by subtracting the reference value of the thickness of the negative electrode sheet 5 from the average value of the thickness of the sheet 5 is obtained, and a total value x + y obtained by adding the obtained values x and y is calculated.

  Next, the control device 81 calculates a correction value a (mm) used when the battery element 1 is wound up based on the total value x + y. In the present embodiment, the correction value a is calculated by substituting the total value x + y into the equation a = − [π × (46-1) × (x + y)] / 2. For example, if x + y is +0.008 mm, the correction value a is about −0.565 mm. The calculated correction value a is stored in the hard disk together with a serial number for specifying the battery element 1.

  Then, the control device 81 controls the circumferential length changing mechanism 91 immediately before the electrode sheets 4 and 5 for one element, which is the basis for calculating the correction value a, are wound, and the calculated correction value a By changing the size L of the gap 13c (14c) from the normal value by the amount, the circumference of the core 13 (14) in which the electrode sheets 4 and 5 for one element are wound is changed. .

  In addition, the calculation formula of the correction value a (mm) in this embodiment is obtained from the following idea. That is, when the winding of the various sheets 2 to 5 is started and the winding proceeds, the circumferential length of the various sheets 2 to 5 wound around the core 13 (14) is the thickness of the various sheets 2 to 5. The length of the various sheets 2 to 5 wound up each time the core 13 (14) makes one rotation gradually increases.

  Here, when it is assumed that the various sheets 2 to 5 are wound on the core 13 (14) at the same time after aligning the starting ends, the reference value of the thickness of the positive electrode sheet 4 is set to 0.15 mm, When the reference value of the thickness of the negative electrode sheet 5 is 0.10 mm and the thickness of the separators 2 and 3 is 0.02 mm, the thickness of the entire area of the electrode sheets 4 and 5 is the same as the reference value. If the core 13 (14) rotates n times (n is a natural number), the length of the various sheets 2 to 5 wound around the core 13 (14) is approximately [(2 × W × n ) + Π × [R × n + n × (n−1) × (0.15 + 0.10 + 0.02 × 2)]]. This value is an ideal value. For example, assuming that the width W is 111.7752 mm and the diameter R is 6 mm, assuming that the core 13 (14) has rotated 30 times, the various sheets 2 to 5 are wound up by approximately 8064 mm. .

  In practice, as will be described later, since the separators 2 and 3, the negative electrode sheet 5 and the positive electrode sheet 4 are wound around the core 13 (14) in this order, The sheets 2 to 5 are not wound on the core 13 (14) at the same time after the starting ends are aligned. That is, by the time the winding of the positive electrode sheet 4 is started, the separators 2 and 3 and the negative electrode sheet 5 are wound to some extent on the core 13 (14). However, the separators 2, 3 and the like wound around the core 13 (14) by the time the winding of the positive electrode sheet 4 is started are relatively short, and the winding when the winding of the positive electrode sheet 4 is started is relatively short. The peripheral length of the separators 2 and 3 wound around the core 13 (14) and the peripheral length of the core 13 (14) itself are not so different. Therefore, in the present embodiment, the circumferential length of the separators 2, 3 and the like wound around the core 13 (14) when winding of the positive electrode sheet 4 is started is set to the circumference of the core 13 (14) itself. It is assumed that the length is the same as the length, and as a result, it is assumed that the various sheets 2 to 5 start winding at the same time as the core 13 (14) after aligning the starting ends.

  Returning to the description of the calculation method, if the thickness of the electrode sheets 4 and 5 is the same as the reference value, the winding amount of the various sheets 2 to 5 will be the above ideal value, but the actual electrode sheets 4 and 5 Variations in the thickness of can occur. Therefore, the average value of the thickness of the positive electrode sheet 4 actually measured is 0.15 + x (mm), and the average value of the thickness of the negative electrode sheet 5 actually measured is 0.10 + y (m). In this case, when the core 13 (14) rotates n times, the lengths of the various sheets 2 to 5 wound around the core 13 (14) are approximately [(2 × W × n) + π × [R × n + n]. × (n−1) × (0.15 + 0.10 + 0.02 × 2 + x + y)]]. Accordingly, with the variation in the thickness of the electrode sheets 4 and 5, the amount of winding is different from the ideal value described above by the amount of π × n × (n−1) × (x + y), and thus the tab 4a. , 5a is also displaced. For example, when the tolerances (allowable values) of both electrode sheets 4 and 5 are ± 0.004 mm, and x and y are +0.004 mm and x + y is +0.008 mm, the core 13 ( 14), the difference of the winding amount from the ideal value (deviation amount) is about 2.26 mm at the time of 10 revolutions, but the deviation amount is about 21. 2 at the time when the core 13 (14) is rotated 30 times. 87 mm (see the graph in FIG. 8 where the correction value a is 0). Thus, the amount of deviation increases at an accelerated rate as the winding proceeds.

  Therefore, in the present embodiment, the increase in the deviation amount is prevented by increasing or decreasing the size L of the gap 13c (14c) and adjusting the circumference of the core 13 (14). Specifically, when the size L of the gap 13c (14c) is adjusted by the correction value a, when the winding core 13 (14) rotates n times, the winding amount becomes the size L of the gap 13c (14c). Compared with the case where the adjustment is not performed, the variation is (2 × a × n). Therefore, when the core 13 (14) rotates n times, the correction value a necessary for eliminating the deviation [π × n × (n−1) × (x + y)] is (2 × a × n ) + [Π × n × (n−1) × (x + y)] = 0, a = − [π × (n−1) × (x + y)] / 2.

  Here, in this embodiment, when the winding of the positive electrode sheet 4 is completed or almost completed in order to align the positions of the tabs 4a and 5a provided on the terminal side of the electrode sheets 4 and 5 that are particularly likely to be displaced. Therefore, the correction value a that can eliminate the shift amount is calculated.

  The minimum number of rotations of the winding core 13 (14) required to complete the winding of the positive electrode sheet 4 is a width W of 111.7752 mm, a diameter R of 6 mm, and the positive electrode sheet 4 for one element. If the thickness of the electrode sheets 4 and 5 is a reference value, the ideal value [(2 × W × n) + π × [R × n + n × (n−1) × ( Based on 0.15 + 0.10 + 0.02 × 2)]], 46 rotations are calculated. Therefore, in this embodiment, a = − [π × (46-1) × () obtained by substituting 46 for n in the formula of a = − [π × (n−1) × (x + y)] / 2. x + y)] / 2, the correction value a is calculated.

  When x + y is +0.008 mm, the correction value a is about −0.565 mm from the above formula, and the circumference of the core 13 (14) is reduced by about 1.1310 mm from the normal value. The By changing the circumference of the core 13 (14) in this way, the amount of deviation can be reduced to almost zero when the core rotates 46 times, and is provided on the terminal side of the electrode sheets 4 and 5. It is possible to align the positions of the tabs 4a and 5a with high accuracy (see the graph in which the correction value a in FIG. 8 is −0.565 mm).

  The method for obtaining the correction value a is an example, and the method for obtaining the correction value a can be changed as appropriate.

  For example, when the positive electrode tab 4a is provided at a portion of 10,000 mm from the starting end of the positive electrode sheet 4 and the position of the positive electrode tab 4a is particularly desired to be aligned, the thicknesses of both the electrode sheets 4 and 5 are the reference values. If the width W and the diameter R are the numerical values exemplified above, the positive electrode sheet 4 is wound at 10000 mm or more at the 37th rotation. Therefore, a = − [π × (37−1) × (x + y)] / 2 obtained by substituting 37 for n in the equation a = − [π × (n−1) × (x + y)] / 2. The correction value a may be calculated based on the following equation. In this case, for example, if x + y is +0.008 mm, the correction value a is about −0.452 mm. By adjusting the size L of the gap 13c (14c) by the amount of the correction value a, the amount of deviation can be made almost zero when the winding core rotates 37 times, and is 10000 mm from the starting end of the positive electrode sheet 4. The positive electrode tab 4a provided in the portion can be accurately arranged at a predetermined position (see the graph in which the correction value a in FIG. 8 is −0.4523 mm).

  Further, for example, the correction value a may be calculated so that the absolute value of the generated deviation amount becomes as small as possible until the winding of the positive electrode sheet 4 is completed. That is, the correction value “a” may be calculated over the entire area of the electrode sheets 4 and 5 so that the respective portions of the electrode sheets 4 and 5 do not deviate as much as possible from the portions of the respective portions that should be normally disposed. For example, when the width W, the diameter R, and the like are the numerical values exemplified above and x + y is +0.008 mm, the correction value a may be about −0.467 mm. In this case, until the winding of the positive electrode sheet 4 is completed, the absolute value of the generated shift amount can be made as small as possible (see the graph in which the correction value a in FIG. 8 is −0.467 mm). ).

  Next, the manufacturing process of the battery element 1 using the winding device 10 described above will be described. The manufacturing process of the battery element 1 is a process of determining a correction value a used when the electrode sheets 4 and 5 for one element are wound based on the thickness of the electrode sheets 4 and 5 for one element ( Correction value determining step) and a step of winding the electrode sheets 4 and 5 for one element (winding step). Note that both these steps are performed at the same time, but in the present embodiment, for convenience of explanation, these two steps will be described separately.

  First, the correction value determination step will be described with reference to the flowchart of FIG. In addition, immediately before the correction value determining step, both the electrode sheets 4 and 5 are gripped by the sheet insertion mechanism 71, and the separators 2 and 3 are the one core 13 (14) to which the electrode sheets 4 and 5 are supplied. Is wound up by a predetermined amount.

  In the correction value determination step, first, in step S11, the negative electrode sheet 5 is supplied to the one core 13 (14) side by the sheet insertion mechanism 71 of the negative electrode sheet supply mechanism 41. Specifically, the sheet insertion mechanism 71 that holds the negative electrode sheet 5 approaches the winding part 11 side, and the negative electrode sheet 5 is inserted between the separators 2 and 3, whereby the negative electrode sheet 5 is supplied. The After the insertion, the holding of the negative electrode sheet 5 by the sheet insertion mechanism 71 is released, and the sheet insertion mechanism 71 returns to the original position.

  With the supply of the negative electrode sheet 5, the negative electrode sheet 5 starts to move between the length measuring rollers 77c and 77d, and in step S12, the thickness measurement mechanism 77 starts measuring the thickness of the negative electrode sheet 5. . That is, the thickness measurement process is started.

  Next, in step S13, after the negative electrode sheet 5 is supplied, when one of the cores 13 (14) rotates a predetermined number of times (for example, one rotation), the sheet insertion mechanism 71 causes the one of the cores 13 (14) side On the other hand, the positive electrode sheet 4 is supplied. Specifically, the sheet insertion mechanism 71 that holds the positive electrode sheet 4 approaches the winding unit 11 side, and the positive electrode sheet 4 is inserted between the separators 2 and 3, whereby the positive electrode sheet 4 is supplied. The Note that after the insertion, the holding of the positive electrode sheet 4 by the sheet insertion mechanism 71 is released, and the sheet insertion mechanism 71 returns to the original position.

  With the supply of the positive electrode sheet 4, the positive electrode sheet 4 starts to move between the length measuring rollers 77c and 77d, and the thickness measurement mechanism 77 starts measuring the thickness of the positive electrode sheet 4 in step S14. The

  When both the electrode sheets 4 and 5 are supplied, the one core 13 (14) is rotated so that the both electrode sheets 4 and 5 are sequentially fed out. Thus, the electrode sheets 4 and 5 pass between the length measuring rollers 77c and 77d, respectively, and the thickness of the electrode sheets 4 and 5 is continuously measured.

  In the subsequent step S15, it is repeatedly determined whether or not the feed amount of the positive electrode sheet 4 from the start of supply has reached a predetermined amount until the condition is satisfied. When an affirmative determination is made in step S15, that is, when the thickness of the entire area along the longitudinal direction of the positive electrode sheet 4 (corresponding to the scheduled winding electrode sheet) for one element is measured, the process proceeds to step S16. And the average value of the measured thickness of the positive electrode sheet 4 is calculated. In addition, supply of the positive electrode sheet 4 with respect to one core 13 (14) will be stopped at the time of affirmation determination in step S15.

  In further subsequent step S <b> 17, the determination as to whether or not the feed amount of the negative electrode sheet 5 from the start of supply has reached a predetermined value is repeated until the condition is satisfied. If an affirmative determination is made in step S17, that is, if the thickness of the entire area along the longitudinal direction of the negative electrode sheet 5 (corresponding to the scheduled winding electrode sheet) for one element is measured, the process proceeds to step S18. And the average value of the thickness of the measured negative electrode sheet 5 is calculated. When an affirmative determination is made in step S17, the supply of the negative electrode sheet 5 to one of the cores 13 (14) is stopped, and the thickness measurement process is ended.

  Next, in step S19, a value x (mm) obtained by subtracting the reference value of the thickness of the positive electrode sheet 4 from the average value of the thickness of the positive electrode sheet 4 obtained in step S16, and the negative value obtained in step S18. A value y (mm) obtained by subtracting the reference value of the thickness of the negative electrode sheet 5 from the average value of the thickness of the electrode sheet 5 is obtained, and a total value x + y obtained by adding the obtained both values x and y is calculated. .

  In subsequent step S20, the correction value a is calculated based on the above-described calculation formula for the correction value a. Thereafter, the obtained correction value a is stored in the hard disk together with the serial number of the battery element 1, and the correction value determination step is terminated.

  Next, the winding process will be described with reference to the flowchart of FIG. Prior to the winding step, the separators 2 and 3 are arranged in the gap 13c (14c) in one of the cores 13 (14) (see FIG. 11).

  In the winding process, first, in step S31, the gap in the one core 13 (14) is equal to the correction value a calculated based on the thickness of the electrode sheets 4 and 5 to be wound from now. The size L of 13c (14c) is increased or decreased.

  Next, in step S32, one core 13 (14) is rotated by a predetermined number, so that the separators 2 and 3 are wound on the one core 13 (14) by a predetermined amount.

  Then, in the subsequent step S33, the negative electrode sheet 5 is supplied to the one core 13 (14) side by the sheet insertion mechanism 71 of the negative electrode sheet supply mechanism 41.

  Next, in step S34, after the negative electrode sheet 5 is supplied, when one of the cores 13 (14) has rotated a predetermined number of times (for example, one rotation), the sheet insertion mechanism 71 causes the one of the cores 13 (14) side. On the other hand, the positive electrode sheet 4 is supplied.

  After the supply of the two electrode sheets 4 and 5, the various sheets 2 to 5 are wound around the one core 13 (14) as the one core 13 (14) rotates.

  In the subsequent step S35, the determination as to whether or not the amount of the positive electrode sheet 4 that has been supplied from the start of supply has reached a predetermined amount is repeated until the condition is satisfied. When an affirmative determination is made in step S35, that is, when the terminal portion of the positive electrode sheet 4 that is currently wound has reached the sheet cutting cutter 72, one core 13 (14) is rotated. The supply of the positive electrode sheet 4 is stopped temporarily.

  Further, in the subsequent step S 36, the positive electrode sheet 4 is gripped by the sheet insertion mechanism 71, and then the positive electrode sheet 4 is cut by the sheet cutting cutter 72. Thereafter, the winding operation of one core 13 (14) is resumed.

  Next, in step S37, the determination as to whether or not the feed amount of the negative electrode sheet 5 from the start of supply has reached a predetermined value is repeated until the condition is satisfied. When an affirmative determination is made in step S 37, that is, when the terminal portion of the negative electrode sheet 5 for one element currently wound reaches the sheet cutting cutter 72, the rotation of one winding core 13 (14). The operation is temporarily stopped and the supply of the negative electrode sheet 5 is stopped.

  In the subsequent step S38, the negative electrode sheet 5 is gripped by the sheet insertion mechanism 71, and then the negative electrode sheet 5 is cut by the sheet cutting cutter 72.

  Next, in step S39, the rotation of one of the winding cores 13 (14) is resumed, whereby the terminal portions (unwinding portions) of the electrode sheets 4 and 5 are wound up.

  In step S40 following step S39, the turret 12 is rotated without the separators 2 and 3 being cut. As a result, one core 13 (14) at the winding position P1 moves toward the removal position P2 while pulling out the separators 2 and 3 from the separator supply mechanisms 51 and 61. On the other hand, the other core 14 (13) at the removal position P2 is moved to the winding position P1 side in a state of being submerged in one table of the turret 12.

  Subsequently, in step S41, in conjunction with the rotation of the turret 12, the wound core 13 (14) of the various sheets 2 to 5 is rotated about its own central axis as the rotation axis.

  Then, in the next step S42, the winding end process is executed to complete the winding process.

  In the winding end process, first, when the number of rotations of one core 13 (14) reaches a predetermined number, the rotation of one core 13 (14) is stopped. Note that the rotation of the turret 12 is stopped before, simultaneously with, or after the rotation of the one core 13 (14).

  When the rotation of the one core 13 (14) and the turret 12 is stopped, as shown in FIG. 12, the one core 13 (14) at the winding position P1 is positioned at the removal position P2, and is removed. The other core 14 (13) at the position P2 is in the winding position P1. Further, at this time, the separators 2 and 3 are placed on one support roller 15b (15a) between the one core 13 (14) and the guide rollers 78a and 78b.

  In this state, the presser roller 17 is brought close to one of the cores 13 (14), the various sheets 2 to 5 are pressed by the presser roller 17, and the separator cutter 16 approaches the separators 2 and 3. 2 and 3 are cut.

  Prior to the cutting of the separators 2 and 3, the other core 14 (13) protrudes from one table of the turret 12, so that the core pieces 14a and 14b (13a and 13b) of the other core 14 (13). ) Between the separators 2 and 3. Further, after adjusting the size L of the gap 14c (13c) by the correction value a corresponding to the electrode sheets 4 and 5 to be wound next time, the other core 14 (13) rotates by a predetermined amount. Thus, the separators 2 and 3 are wound around the outer periphery of the other core 14 (13) by a predetermined amount. In the next winding step, the electrode sheets 4 and 5 are supplied to the other core 14 (13) around which the separators 2 and 3 are wound.

  After the separators 2 and 3 are cut, one core 13 (14) is rotated while the sheets 2 to 5 are being pressed by the pressing roller 17. Thus, the end portions of the separators 2 and 3 and the electrode sheets 4 and 5 are completely wound up without being scattered. Thereafter, the tape pasting mechanism 18 stops the end portions of the separators 2 and 3 with the fixing tape, and the winding end process is completed.

  As described above in detail, according to the present embodiment, it is possible to more reliably prevent the respective portions of the electrode sheets 4 and 5 from being greatly displaced from the positions where they are normally disposed.

  For example, when the measured thickness of the electrode sheets 4 and 5 is relatively large and the total value x + y becomes a positive number, that is, as the winding proceeds, as shown in FIG. The forward direction (hereinafter simply referred to as “front side”) of the winding core 13 (14) gradually from the position (position on the dotted line in FIG. 13) where the respective portions Z1, Z2, Z3 along the longitudinal direction should be normally disposed. ), The correction value a is a negative number, and the circumference of the core 13 (14) is relatively small. Accordingly, at the beginning of winding, the respective portions Z1, Z2, Z3 in the electrode sheets 4, 5 are located on the rear side in the rotational direction of the core 13 (14) with respect to the position where they are normally disposed (hereinafter simply referred to as “rear side”). Will be arranged). And even if each part Z1, Z2, Z3 of the electrode sheets 4, 5 gradually shifts to the front side as the winding advances as much as the arrangement position shifts to the rear side in this way. The deviation is absorbed. As a result, it is possible to make it more unlikely that the respective portions Z1, Z2, and Z3 of the electrode sheets 4 and 5 are arranged so as to be largely displaced forward from the positions where they are normally arranged.

  On the other hand, when the measured thicknesses of the electrode sheets 4 and 5 are relatively small and the total value x + y becomes a negative number, that is, as shown in FIG. When the portions Z1, Z2, and Z3 are to be disposed gradually rearward from the positions (positions on the dotted line in FIG. 14) that should be normally disposed, the correction value a is a positive number, and the core 13 The circumference of (14) is assumed to be relatively large. Thereby, at the beginning of winding, the respective portions Z1, Z2, and Z3 in the electrode sheets 4 and 5 are disposed on the front side from the positions where they are normally disposed. And even if each site | part Z1, Z2, Z3 of the electrode sheets 4 and 5 gradually shift | displaces to the back side by winding to the extent that arrangement | positioning position has shifted | deviated to the front side in this way, The deviation is absorbed. As a result, it is possible to make it less likely that the respective portions Z1, Z2, and Z3 of the electrode sheets 4 and 5 are arranged to be largely shifted rearward from the positions where they are normally arranged.

  As a result, the tabs 4a and 5a can be more reliably arranged within a predetermined range along the circumferential direction of the battery element 1. In particular, in the present embodiment, by calculating the correction value a as described above, the tabs 4a and 5a provided on the terminal side of the electrode sheets 4 and 5 that are particularly likely to be displaced are accurately brought into a predetermined range. Can be arranged.

  Further, the thickness of the electrode sheets 4 and 5 before being wound is measured by the thickness measuring mechanism 77. Therefore, the thickness of the electrode sheets 4 and 5 can be measured more accurately, and the correction value a and the circumference of the cores 13 and 14 can be set more appropriately.

  Further, the thickness of the entire electrode sheet 4, 5 for one element before winding is measured in advance, and the winding core is based on the thickness measured in advance when the electrode sheets 4, 5 are wound. The peripheral lengths 13 and 14 are controlled. Therefore, the circumference of the cores 13 and 14 can be optimized according to the thickness of the wound electrode sheets 4 and 5. As a result, the tabs 4a and 5a can be more reliably arranged within a predetermined range.

  In addition, since the circumferential length changing mechanism 91 in the present embodiment has a relatively simple configuration, the winding device 10 can be simplified, and an increase in cost can be suppressed.

Further, the correction value a used when obtaining each battery element 1 can be easily grasped by collating the contents of the hard disk in the control device 81 with the serial number given to the fixing tape.
[Second Embodiment]
Next, the second embodiment will be described focusing on the differences from the first embodiment. In the first embodiment, the displacement of the tabs 4a and 5a is adjusted by adjusting the size L of the gap 13c (14c) by the correction value a calculated based on the thickness of the positive electrode sheets 4 and 5. Suppression is achieved. On the other hand, in the second embodiment, the displacement of the tabs 4a and 5a can be suppressed by adjusting the tension applied to the electrode sheets 4 and 5 during winding according to the thickness of the electrode sheets 4 and 5. It has been.

  Specifically, in the second embodiment, when the control device 81 winds the various sheets 2 to 5 based on the total value x + y, the various sheets 2 to 5 are applied by the tension applying mechanism 73 as a tension applying unit. The tension T (N) to be applied to is determined. The tension T is determined in consideration of a tension determination table (see FIG. 15) indicating the correspondence between the total value x + y and the tension T stored in advance in the RAM. For example, when the total value x + y is not less than the value ST1 and less than the value ST2, the value T2 is determined as the tension T. Further, the determined tension T is stored in the hard disk together with a serial number for specifying the battery element 1.

  In the tension determination table, the larger the total value x + y, the larger the tension T is set, and the positions of the tabs 4a and 5a are substantially constant corresponding to the variation in the thickness of the electrode sheets 4 and 5. Are set for each range of the total value x + y. For example, when the total value x + y is greater than or equal to the value ST0 and less than the value ST1, the tabs 4a and 5a of the battery element 1 obtained by winding while applying the tension T1 corresponding to this range to the various sheets 2 to 5 When the position and the total value x + y are not less than the value ST2 and less than the value ST3, the tabs 4a and 5a in the battery element 1 obtained by winding the tension T3 corresponding to this range while applying to the various sheets 2 to 5 are obtained. It is comprised so that it may correspond with the position of. Instead of the tension determination table, a mathematical expression that can derive the tension to be applied by substituting the total value x + y may be used.

  In the winding process, the control device 81 controls the tension applying mechanism 73 (dancer roller 73c) to apply the determined tension T to the various sheets 2 to 5 while winding the various sheets 2 to 5 Will be performed. In the second embodiment, the size L of the gap 13c (14c) is always constant.

  As described above, according to the second embodiment, at the time of winding, the tension T based on the thickness of the electrode sheets 4 and 5 is applied to the various sheets 2 to 5, whereby each part of the electrode sheets 4 and 5 is It can prevent more reliably that it will shift | deviate greatly from the position which should be arrange | positioned normally.

  For example, in the second embodiment, when the measured thickness of the electrode sheets 4 and 5 is relatively large, that is, as the winding progresses, each part of the electrode sheets 4 and 5 is more than the position where it should normally be arranged. However, the tension T is relatively large when it is gradually arranged on the front side. Thereby, at the time of winding, it becomes easy to arrange each part of electrode sheets 4 and 5 on the back side, and can make the said part correspond to the position which should be usually arranged, or can be brought closer.

  In addition, for example, when the measured thickness of the electrode sheet is relatively small, that is, as the winding proceeds, the respective portions of the electrode sheet are gradually arranged on the rear side from the positions where they should be normally arranged. In such a case, the tension T is relatively small. Thereby, at the time of winding, each part of the electrode sheets 4 and 5 can be easily arranged on the front side, and the respective parts can be made to coincide with or closer to the positions where they should normally be arranged.

  As a result, as in the first embodiment, the tabs 4a and 5a can be more reliably arranged within a predetermined range along the circumferential direction of the battery element 1.

  In addition, the tension T is determined based on the thickness of the entire electrode sheets 4 and 5 for one element before winding. Therefore, the tension T can be optimized according to the thickness of the wound electrode sheets 4 and 5, and the tabs 4a and 5a can be more reliably arranged within a predetermined range.

  In addition, it is not limited to the description content of the said embodiment, For example, you may implement as follows. Of course, other application examples and modification examples not illustrated below are also possible.

  (A) In the above embodiment, the displacement of the tabs 4a, 5a is suppressed by adjusting the circumferential length of the cores 13, 14 or the tension applied to the various sheets 2-5. You may comprise so that position shift of tab 4a, 5a can be suppressed more reliably by adjusting both the circumferential length of 13 and 14, and the tension | tensile_strength provided to various sheets 2-5.

  (B) The tabs 4a and 5a in the above embodiment are configured to be arranged in two rows in the ideal state, but the arrangement positions of the tabs 4a and 5a in the ideal state can be changed as appropriate.

  (C) In the above embodiment, the correction value a and the tension T are determined based on the thickness of the electrode sheets 4 and 5 before winding, but the thickness (obtained) of the electrode sheets 4 and 5 after winding. On the basis of the thickness of the electrode sheets 4 and 5 in the battery element 1 obtained, the correction value a and the tension T used in the subsequent winding may be determined. That is, based on the thickness of the electrode sheets 4 and 5 in the obtained battery element 1, the correction value a and the tension T used at the next and subsequent windings may be feedback controlled. In addition, the thickness of the electrode sheets 4 and 5 after winding can be obtained by analyzing a captured image of the end face of the battery element 1 or the like.

  Further, for example, the thicknesses of the electrode sheets 4 and 5 constituting the raw sheets 32 and 42 may be measured in advance, and the correction value a and the like may be determined based on the previously measured thickness.

  (D) In the above embodiment, the size L of the gap 13c (14c) is adjusted in a state where the separators 2 and 3 are arranged in the gap 13c (14c). 14) is configured to adjust the size L of the gap 13c (14c) after it starts to move from the removal position P2 to the winding position P1 until it protrudes from one table of the turret 12. Also good.

  (E) As long as the correction value a and the tension T are determined based on the thicknesses of the electrode sheets 4 and 5, methods other than those described in the above embodiment may be used. Therefore, for example, the correction value a or the like may be determined based on the thicknesses of the electrode sheets 4 and 5 measured for a certain period of time or every certain transport amount. Further, it is not always necessary to determine the correction value a or the like based on the total value as in the above embodiment, and the correction value a or the like may be determined based on the individual thicknesses of the electrode sheets 4 and 5.

  (F) In the above embodiment, the tabs 4a and 5a are joined to the electrode sheets 4 and 5 by welding (so-called welded tabs), but the configuration of the tabs is not limited to this. Therefore, for example, tabs (so-called cut tabs) formed between the cuts in the electrode sheet by intermittently providing cuts at the end portions in the width direction of the electrode sheet may be used.

  (G) In the above embodiment, the circumference changing mechanism 91 is configured such that only one core piece 13a (14a) moves, but both the core pieces 13a, 13b (14a, 14b) can move. You may comprise.

  (H) In the above embodiment, the winding core 13 (14) is rotated while the separators 2 and 3 are disposed between the core pieces 13a and 13b (14a and 14b) at the start of winding of the various sheets 2 to 5. Thus, the separators 2 and 3 are wound around the winding core 13 (14) by a predetermined amount. On the other hand, gripping means capable of gripping the separators 2 and 3 is provided on the core 13 (14), and the cores are gripped by the gripping means when the sheets 2 to 5 are started to be wound. The separators 2 and 3 may be wound up by a predetermined amount by rotating 13 (14). Further, the holding means may be configured to start winding after holding both the electrode sheets 4 and 5 together with the separators 2 and 3.

  (I) In the above-described embodiment, the winding unit 11 includes the two winding cores 13 and 14, but the number of winding cores is not limited to this, and one or three winding cores are provided. It is good also as a structure provided with two or more winding cores.

  (J) In the above embodiment, the battery device 1 of the lithium ion battery is manufactured by the winding device 10, but the winding device manufactured by the winding device 10 is not limited to this. For example, Alternatively, a wound element or the like of an electrolytic capacitor may be manufactured.

  (K) The outer peripheral shape of the cores 13 and 14 is not particularly limited, and can be changed as appropriate. For example, you may employ | adopt the core whose outer periphery shape becomes circular shape, elliptical shape, etc., for example.

  (L) The material of the separators 2 and 3 and the electrode sheets 4 and 5 is not limited to the said embodiment. For example, in the above embodiment, the separators 2 and 3 are made of PP, but the separators 2 and 3 may be made of other insulating materials. Further, for example, the active material applied to the electrode sheets 4 and 5 may be appropriately changed.

  DESCRIPTION OF SYMBOLS 1 ... Battery element (winding element), 2, 3 ... Separator, 4, 5 ... Electrode sheet, 4a ... Positive electrode tab (tab), 5a ... Negative electrode tab (tab), 10 ... Winding device, 13, 14 ... Core, 13a, 13b, 14a, 14b ... Core piece, 73 ... Tension applying mechanism (tension applying means), 77 ... Thickness measuring mechanism (thickness measuring means), 77c ... First length measuring roller, 77d ... Second Length measuring roller, 81... Control device (control means), 91. Circumference changing mechanism (peripheral length changing means), 92.

Claims (5)

A strip-shaped electrode sheet having a predetermined tab and having an active material on the surface and a strip-shaped separator made of an insulating material are supplied from a predetermined supply mechanism to a rotatable core with its own central axis as a rotation axis. And a winding device that winds the electrode sheet and the separator while being stacked by rotating the winding core,
A circumferential length changing means capable of changing a length along the rotation direction of a portion of the winding core around which the electrode sheet and the separator are wound,
A thickness measuring means for measuring the thickness of the electrode sheet;
By controlling the circumferential length changing means based on the measurement result by the thickness measuring means, the winding sheet is wound along the rotation direction of the part where the electrode sheet and the separator are wound. Control means for controlling the length;
A winding device comprising: The thickness measuring means measures the thickness of the entire area of the electrode sheet scheduled to be wound, which is the electrode sheet for one element before winding, in the transport path of the electrode sheet upstream of the winding core. ,
The control means controls the circumference changing means based on a measurement result on the scheduled winding electrode sheet by the thickness measuring means, so that the winding core of the winding scheduled electrode sheet is wound. The winding device according to claim 1, wherein the winding device is configured to control a length along the rotation direction of a portion where the electrode sheet and the separator are wound. The winding core includes two core pieces provided in a state extending in the direction of the rotation axis and arranged in a direction orthogonal to the rotation axis,
The circumference changing means moves one of the cores in the contact / separation direction with respect to the other core, so that the rotation direction of the portion of the core where the electrode sheet and the separator are wound is rotated. The winding device according to claim 1, wherein the winding device is configured to change a length along the line. The thickness measuring means includes
A first length measuring roller that is hung on the outer periphery in a state in which the electrode sheet is bent, and rotates as the electrode sheet is conveyed;
A second length measuring roller disposed so as to sandwich the electrode sheet with the first length measuring roller, and rotating with the conveyance of the electrode sheet;
When the electrode sheet passes between the two length measuring rollers, the rotation amount of the first length measuring roller that contacts the inner peripheral surface of the electrode sheet and the second measurement that contacts the outer peripheral surface of the electrode sheet. The winding device according to any one of claims 1 to 3 , wherein the winding device is configured to measure a thickness of the electrode sheet based on a difference from a rotation amount of the long roller. Along the rotation direction of the portion around which the belt-like electrode sheet having a predetermined tab and having an active material on the surface and the belt-like separator made of an insulating material is wound, which is rotatable about its central axis as a rotation axis Manufacturing of a winding element for manufacturing a winding element formed by winding the electrode sheet and the separator around the winding core using a winding device including a winding core whose length can be changed A method,
A thickness measuring step for measuring the thickness of the electrode sheet;
A winding step of winding the electrode sheet and the separator,
In the winding step, based on the measurement result of the thickness measurement step, the length along the rotation direction of the portion of the core where the electrode sheet and the separator are wound is controlled. A method for manufacturing a wound element.

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