Winding device

Abstract

To provide a winding device that can more reliably prevent collision of tabs with an outer peripheral surface of a transfer roller, and can effectively prevent breaking of the tabs.SOLUTION: A winding device comprises a rotatable winding core, and electrode sheets 4, 5 having tabs 4b, 5b are supplied to the winding core while being accelerated or decelerated. The winding device includes a rotatable transfer roller 711, an outer peripheral surface of which is covered by the electrode sheets 4, 5, and that defines a conveyance path of the electrode sheets 4, 5, and a position adjustment part 712 that can adjust the position of the transfer roller 711 along a rotation axis direction of the transfer roller 711. The position adjustment part 712 adjusts the relative positional relationship between the transfer roller 711 and the electrode sheets 4, 5 covering the transfer roller 711, so that valley parts 4c, 5c of the electrode sheets 4, 5 protrude from width directional edge 711e of the outer peripheral surface of the transfer roller 711.SELECTED DRAWING: Figure 10

Description

[Technical Field]

[0001] The present invention relates to a winding device for obtaining a wound element to be built into, for example, a secondary battery or the like. [Background technology]

[0002] For example, a wound element used in a secondary battery such as a lithium ion battery is manufactured by winding a positive electrode sheet coated with a positive electrode active material and a negative electrode sheet coated with a negative electrode active material, which are stacked together with a separator sheet made of an insulating material interposed therebetween.

[0003] Known electrode sheets include an electrode body having an active material on its surface and tabs protruding from the widthwise edges of the electrode body, with multiple tabs spaced apart along the length of the electrode body.

[0004] Furthermore, a known winding device for manufacturing wound elements includes a rotatable core and a supply mechanism for supplying an electrode sheet and a separator sheet to the core. Such a winding device is provided with freely rotatable transfer rollers on which the electrode sheet or the like is hung, and the transfer rollers serve to determine a transport path for the electrode sheet or the like.

[0005] However, when an electrode sheet having a tab passes through a transfer roller, the tab may bend. To address this problem, a technology has been proposed in which a deformation prevention member is provided at a position on the transfer roller that corresponds to the entrance of the electrode sheet (see, for example, Patent Document 1). The deformation prevention member is provided apart from the outer peripheral surface of one end of the transfer roller in the width direction. The tab is guided between the deformation prevention member and the transfer roller, thereby preventing the tab from being broken. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-35892 Summary of the Invention [Problem to be solved by the invention]

[0007] However, after extensive research, the inventors of the present invention have identified the following factors as the causes of the folding of the tab.

[0008] That is, when the electrode sheet is wound, it is not always transported at a constant speed, but is transported while being accelerated and decelerated. Such acceleration and deceleration of the electrode sheet causes vibration and resonance in the electrode sheet, which in turn causes the tabs to oscillate along the thickness direction of the electrode sheet. When the oscillating tabs collide with the outer peripheral surface of the transport roller, they jump up, resulting in the tabs being bent.

[0009] In this regard, the technology described in Patent Document 1 does not solve the problem of the tab colliding with the outer circumferential surface of the transfer roller and being thrown up. In fact, the thrown up tab may collide with the deformation prevention member, causing deformation or breakage of the tab.

[0010] The present invention has been made in consideration of the above circumstances, and its object is to provide a winding device that can more reliably prevent the tab from colliding with the outer peripheral surface of the transfer roller and effectively prevent the tab from breaking. [Means for solving the problem]

[0011] The following describes each of the means suitable for achieving the above object, with specific effects of the corresponding means added as necessary.

[0012] Means 1. Equipped with a rotatable core, A winding device that supplies a strip-shaped electrode sheet, which includes an electrode main body having an active material on its surface and a plurality of tabs protruding from widthwise edge portions of the electrode main body and provided at intervals along the longitudinal direction of the electrode main body, and a strip-shaped separator sheet made of an insulating material to a winding core while rotating the winding core, and overlaps and winds the electrode sheet and the separator sheet, The electrode sheet is configured to be supplied to the winding core while being accelerated or decelerated, a rotatable transfer roller having an outer circumferential surface on which the electrode sheet is hung and defining a transfer path for the electrode sheet; a position adjusting means for adjusting the position of the transfer roller along the rotation axis of the transfer roller, A winding device characterized in that the position adjustment means adjusts the relative positional relationship between the transfer roller and the electrode sheet hung on the transfer roller, so that a valley portion, which is a widthwise edge portion of the electrode main body portion located between the plurality of tabs, is set to protrude from the widthwise edge portion of the outer surface of the transfer roller.

[0013] According to the above-mentioned method 1, the electrode sheet is supplied to the core while being accelerated and decelerated. Therefore, vibrations and resonances caused by the acceleration and deceleration of the electrode sheet cause the tab to vibrate, which may result in the tab colliding with the outer peripheral surface of the transfer roller and causing the tab to break.

[0014] In this regard, according to the above-mentioned means 1, the winding device has a position adjustment means capable of adjusting the position of the transfer roller along the rotation axis direction of the transfer roller. By using this position adjustment means to adjust the relative positional relationship between the transfer roller and the electrode sheet, the valleys, which are the widthwise edge portions of the electrode main body and the portions located between the tabs, are set to extend beyond the widthwise edge portions of the outer peripheral surface of the transfer roller. In other words, when the transfer roller is viewed from a direction perpendicular to the rotation axis of the transfer roller, the entire tab of the electrode sheet hung on the transfer roller is set to be located outside the outer peripheral surface of the transfer roller. Therefore, even if the tab vibrates, the tab can be more reliably prevented from colliding with the outer peripheral surface of the transfer roller. As a result, the tab can be prevented from jumping up due to a collision with the outer peripheral surface of the transfer roller, and thus, the tab can be effectively prevented from breaking.

[0015] Furthermore, since the tab is prevented from colliding with the outer peripheral surface of the transfer roller, the tab is prevented from breaking and can be maintained in good condition with less damage, thereby improving the quality of the wound element obtained.

[0016] Furthermore, by providing a position adjustment means, it becomes possible to accommodate various electrode sheets with different widths, etc., thereby improving convenience.

[0017] Means 2: A position detection means for detecting the widthwise position of the electrode sheet hung on the transfer roller; a correction means for correcting a positional deviation of the electrode sheet in the width direction while the electrode sheet is being wound around the winding core, based on the position detected by the position detection means, The winding device described in means 1 is configured so that the position detection means and the correction means can maintain a state in which the valley portion protrudes from the widthwise edge portion of the outer peripheral surface of the transfer roller.

[0018] According to the above-mentioned means 2, the position detection means and the correction means can maintain the state in which the valleys protrude from the widthwise edge of the outer peripheral surface of the transfer roller. Therefore, it is possible to more reliably prevent the tab from colliding with the outer peripheral surface of the transfer roller. This further enhances the effect of preventing the tab from breaking and improves the condition of the tab.

[0019] Means 3. The winding device described in Means 1, characterized in that the electrode sheet transported horizontally or diagonally horizontally is hung on the transport roller at a position immediately upstream of the transport roller along the transport direction of the electrode sheet.

[0020] According to the above-mentioned method 3, the electrode sheet is transported horizontally or diagonally horizontally at the position immediately upstream of the transport roller. Therefore, the tab of the electrode sheet is likely to droop at the position immediately upstream of the transport roller, which may increase the likelihood of the tab colliding with the outer peripheral surface of the transport roller.

[0021] In this regard, by employing the above-mentioned means 1, it is possible to more reliably prevent the tab from colliding with the transfer roller even under conditions that tend to cause the tab to droop, as in the above-mentioned means 3. In other words, it can be said that the above-mentioned means 1 functions particularly effectively when the electrode sheet that is transported horizontally or obliquely horizontally is hung on the transfer roller at a position immediately upstream of the roller.

[0022] Means 4. The tab is formed by cutting a strip-shaped electrode sheet material having an active material on its surface, the valley portion is constituted by a cut surface formed by the cutting process, The winding device described in means 1 is characterized in that the winding core is used to wind the electrode sheet in which the valley portion is formed by the cut surface.

[0023] According to the above-mentioned method 4, the tab is formed by cutting the electrode sheet material using a laser, a mold, or the like, and the valley portion is formed by the cut surface formed by the cutting process. Therefore, the valley portion is likely to be rough (having burrs, etc.).

[0024] In this regard, by adopting the above-mentioned means 1, even if the valley portion is rough, the rough portion (for example, burrs) can be more reliably prevented from climbing up onto the outer peripheral surface of the transfer roller, thereby more reliably preventing the tab from breaking due to the rough portion climbing up onto the outer peripheral surface of the transfer roller, and as a result, the effect of preventing the tab from breaking can be further improved.

[0025] Furthermore, there is no need to perform processing to remove the roughened portions from the valleys (cut surfaces) in order to prevent the roughened portions from riding on the outer circumferential surface of the transfer roller, which reduces the manufacturing costs of the wound element.

[0026] Means 5. The winding device described in Means 1, characterized in that the transfer roller is supported in a cantilevered state only at one end along the rotation axis direction, the end opposite the side on which the tab is arranged.

[0027] According to the above-mentioned feature 5, the transfer roller is supported in a cantilevered state only at the end opposite to the side where the tab is located. Therefore, there is no part supporting the transfer roller on the side where the tab is located, and therefore the tab does not collide with that part. This more reliably prevents the tab from colliding not only with the outer circumferential surface of the transfer roller, but also with the part supporting the transfer roller. As a result, the tab can be more effectively prevented from breaking.

[0028] Means 6. The position adjusting means is a rod-shaped shaft portion extending in the direction of the rotation axis; a bearing attached to the transfer roller with the shaft portion inserted therethrough, and supporting the transfer roller in a freely rotatable state relative to the shaft portion; a set collar that can be switched between a state in which sliding movement of the bearing along the shaft portion is restricted and a state in which restriction of the sliding movement is released, The winding device described in means 1 is characterized in that it is configured so that the relative positional relationship between the transfer roller and the electrode sheet hung on the transfer roller can be adjusted by sliding the bearing along the shaft portion.

[0029] According to the above-mentioned means 6, the position adjusting means can be realized with a relatively simple configuration, which makes it possible to reduce the costs involved in manufacturing and maintaining the winding device and to make the device more compact.

[0030] Furthermore, the transfer roller can be slid continuously (analogly) by means of the above-mentioned means 6. This allows for fine adjustment of the relative positional relationship between the electrode sheet and the transfer roller, and ultimately allows for more appropriate setting of the relative positional relationship.

[0031] The technical matters relating to the above means may be combined as appropriate. For example, the technical matters relating to the above means 2 may be combined with the technical matters relating to the above means 5. [Brief explanation of the drawings]

[0032] [Figure 1] FIG. 2 is a perspective view showing a schematic configuration of a battery element. [Figure 2] FIG. 2 is a plan view showing a schematic configuration of a positive electrode sheet. [Figure 3] FIG. 2 is a plan view showing a schematic configuration of a negative electrode sheet. [Figure 4] FIG. 10 is a schematic plan view showing how tabs of the positive electrode sheet are formed by cutting the positive electrode sheet material. [Figure 5] FIG. 10 is a schematic plan view showing how tabs of a negative electrode sheet are formed by cutting a negative electrode sheet material. [Figure 6] FIG. 2 is a schematic diagram of a winding device. [Figure 7] FIG. 2 is a schematic diagram of a winding section. [Figure 8] FIG. [Figure 9] FIG. 9 is a cross-sectional view taken along the line JJ in FIG. 8. [Figure 10] 10 is a schematic plan view showing the positional relationship between the valleys of the electrode sheet and the widthwise edge of the outer circumferential surface of the transfer roller. FIG. [Figure 11] FIG. 2 is a schematic front view of a correction unit. [Figure 12] FIG. 10 is a schematic diagram of a winding section when a separator sheet is placed in a gap in the winding core. [Figure 13] FIG. 10 is a schematic diagram of a winding section when cutting a separator sheet. [Figure 14] FIG. 10 is a schematic diagram of the winding section when winding of the electrode sheet and the like is completed. [Figure 15] 10 is a schematic perspective view of a roller device and the like illustrating a position adjustment mechanism according to another embodiment. FIG. [Figure 16] FIG. 16 is a cross-sectional view taken along the line KK in FIG. 15. [Figure 17] FIG. 10 is a schematic perspective view of a roller device illustrating a position adjustment mechanism according to another embodiment. [Figure 18] FIG. 10 is a partially cutaway front view of a roller device showing a transfer roller in another embodiment. [Figure 19] FIG. 10 is a partially cutaway front view of a roller device showing a transfer roller in another embodiment. [Figure 20] FIG. 10 is a perspective schematic view of a roller device and the like showing a transfer roller supported in a cantilevered state in another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0033] An embodiment will be described below with reference to the drawings. First, the structure of a lithium ion battery element as a wound element obtained by a winding device will be described.

[0034] As shown in FIG. 1, a lithium-ion battery element 1 (hereinafter simply referred to as "battery element 1") is manufactured by winding a positive electrode sheet 4 and a negative electrode sheet 5 in a stacked state with two separator sheets 2 and 3 interposed therebetween. In this embodiment, the positive electrode sheet 4 and the negative electrode sheet 5 each correspond to an "electrode sheet." Note that, instead of the two separator sheets 2 and 3, a single folded separator sheet may be used. Furthermore, for convenience of explanation, hereinafter, the separator sheets 2 and 3 and the electrode sheets 4 and 5 may be referred to as "various sheets 2 to 5."

[0035] The separator sheets 2 and 3 are strip-shaped and have the same width, and are made of an insulating material such as polypropylene (PP) to prevent the different electrode sheets 4 and 5 from coming into contact with each other and causing a short circuit.

[0036] Each of the electrode sheets 4, 5 is made of a thin metal sheet, with, for example, an aluminum foil sheet being used for the positive electrode sheet 4 and a copper foil sheet being used for the negative electrode sheet 5. Each of the electrode sheets 4, 5 is relatively thin (for example, 5 to 50 μm or 10 to 30 μm thick).

[0037] In addition, as shown in FIGS. 2 and 3, each of the electrode sheets 4 and 5 includes an electrode main body 4a or 5a and a tab 4b or 5b.

[0038] The electrode main bodies 4a, 5a have approximately the same width as the separator sheets 2, 3, and an active material is applied to both the front and back surfaces of the electrode main bodies 4a, 5a. The electrode main body 4a of the positive electrode sheet 4 is applied with a positive electrode active material (e.g., lithium manganate particles, etc.) (the applied portion of the active material is indicated by a dotted pattern in Figures 2, 3, etc.). The electrode main body 5a of the negative electrode sheet 5 is applied with a negative electrode active material (e.g., activated carbon, etc.). Ion exchange between the positive electrode sheet 4 and the negative electrode sheet 5 is enabled via the active material. Note that Figures 2 and 3 show a configuration in which the active material is not applied to a portion of the electrode main bodies 4a, 5a (e.g., the widthwise edge portions), but the active material may be applied to the entire area of ​​the electrode main bodies 4a, 5a.

[0039] The tabs 4b, 5b protrude from the widthwise edge of the electrode main bodies 4a, 5a and are provided at intervals along the longitudinal direction of the electrode main bodies 4a, 5a. In this embodiment, the tab 4b of the positive electrode sheet 4 protrudes from one widthwise edge of the electrode main body 4a, and the tab 5b of the negative electrode sheet 5 protrudes from the other widthwise edge of the electrode main body 5a. Note that both tabs 4b, 5b may be configured to protrude from the same edge of the electrode main bodies 4a, 5a.

[0040] As shown in FIGS. 4 and 5, the tabs 4b of the positive electrode sheet 4 are formed by cutting a strip-shaped positive electrode sheet material 4x having a positive electrode active material on its surface using a laser, a mold, or the like (for example, by cutting the positive electrode sheet material 4x along the two-dot chain lines in FIG. 4). Similarly, the tabs 5b of the negative electrode sheet 5 are formed by cutting a negative electrode sheet material 5x having a negative electrode active material on its surface. Therefore, the widthwise edge portions of the electrode main bodies 4a and 5b extending along the longitudinal direction of the electrode sheets 4 and 5, and the valleys 4c and 5c located between the tabs 4b and 5b, are formed by cut surfaces formed by the cutting process. The valleys 4c and 5c formed by the cut surfaces may have burrs or the like and may be rough. In this embodiment, the positive electrode sheet material 4x and the negative electrode sheet material 5x each correspond to the "electrode sheet material."

[0041] To obtain a lithium-ion battery, the battery element 1 is placed in a cylindrical metal battery container (case) (not shown), and the tabs 4b and 5b are bundled together. If necessary, the bundled tabs 4b and 5b are welded together. The bundled tabs 4b are then connected to a positive electrode terminal component (not shown), and the bundled tabs 5b are connected to a negative electrode terminal component (not shown). The two terminal components are then positioned to close both end openings of the battery container, thereby obtaining a lithium-ion battery.

[0042] Next, a description will be given of a winding device 10 for manufacturing the battery element 1. As shown in Fig. 6, the winding device 10 includes a winding section 11 for winding the various sheets 2 to 5, a positive electrode sheet supply mechanism 31 for supplying the positive electrode sheet 4 to the winding section 11, a negative electrode sheet supply mechanism 41 for supplying the negative electrode sheet 5 to the winding section 11, separator supply mechanisms 51 and 61 for supplying the separator sheets 2 and 3 to the winding section 11, respectively, and a control device 91. The operation of various mechanisms within the winding device 10, such as the winding section 11 and the supply mechanisms 31, 41, 51, and 61, is controlled by the control device 91.

[0043] The positive electrode sheet supply mechanism 31 includes a positive electrode sheet raw sheet 32 ​​in which the positive electrode sheet 4 is wound in a roll shape. The positive electrode sheet raw sheet 32 ​​is supported so as to be freely rotatable, and the positive electrode sheet 4 is pulled out from there as needed.

[0044] The positive electrode sheet supply mechanism 31 includes a roller device 71, a positional relationship maintaining mechanism 72, a sheet inserting mechanism 73, a sheet cutting cutter 74, a tension applying mechanism 75, and a buffer mechanism .

[0045] The roller device 71 is a device having the positive electrode sheet 4 wrapped around its outer periphery and including transfer rollers 711 for determining a transport path for the positive electrode sheet 4. A plurality of roller devices 71 (transfer rollers 711) are provided along the transport path for the positive electrode sheet 4. The configuration of the roller device 71 will be described in detail later.

[0046] The positional relationship maintaining mechanism 72 is provided immediately upstream of the transfer roller 711 along the transport path of the positive electrode sheet 4, and serves to maintain an appropriate positional relationship between the outer circumferential surface of the transfer roller 711 and the positive electrode sheet 4 hung thereon. The configuration of the positional relationship maintaining mechanism 72 will also be described later.

[0047] The sheet insertion mechanism 73 is for feeding the positive electrode sheet 4 to the winding unit 11 while holding it.

[0048] The sheet cutting cutter 74 is used to cut the positive electrode sheet 4. The cutting of the positive electrode sheet 4 is performed while the positive electrode sheet 4 is being held by the sheet insertion mechanism 73. The sheet cutting cutter 74 can be separated from the conveyance path of the positive electrode sheet 4 so as not to interfere with the supply of the positive electrode sheet 4 by the sheet insertion mechanism 73.

[0049] The tension applying mechanism 75 is provided with a plurality of rollers (for example, dancer rollers) for applying tension to the positive electrode sheet 4. The operation of these rollers is controlled by a control device 91, thereby making it possible to adjust the tension applied by the tension applying mechanism 75 to the positive electrode sheet 4. In this embodiment, the tension applying mechanism 75 is configured to always apply a constant tension to the positive electrode sheet 4. Note that the rollers constituting the tension applying mechanism 75 may be configured similarly to the transfer roller 711 in terms of their relative positional relationship with the positive electrode sheet 4.

[0050] The buffer mechanism 76 has, for example, a pair of driven rollers and a lifting roller disposed between the rollers so as to be displaceable in the up and down direction, and is used to temporarily store the positive electrode sheet 4. Note that the rollers constituting the buffer mechanism 76 may have the same configuration as the transfer roller 711 in terms of their relative positional relationship with the positive electrode sheet 4.

[0051] The negative electrode sheet supply mechanism 41 is provided, at its most upstream side, with a negative electrode sheet raw material 42 in which the negative electrode sheet 5 is wound in a roll shape. The negative electrode sheet raw material 42 is supported so as to be freely rotatable, and the negative electrode sheet 5 is pulled out from there as appropriate.

[0052] Further, in the middle of the conveyance path for the negative electrode sheet 5 from the negative electrode sheet raw roll 42 to the winding unit 11, a roller device 71, a positional relationship maintaining mechanism 72, a sheet inserting mechanism 73, a sheet cutting cutter 74, a tension applying mechanism 75, a buffer mechanism 76, and the like are provided, similar to the conveyance path for the positive electrode sheet 4. These are the same as those provided in the conveyance path for the positive electrode sheet 4, except that they function for the negative electrode sheet 5.

[0053] On the other hand, the separator supply mechanisms 51, 61 are provided with separator raw rolls 52, 62 each formed by winding up the separator sheets 2, 3 in a roll shape. The separator raw rolls 52, 62 are supported so as to be freely rotatable, and the separator sheets 2, 3 are pulled out from them as appropriate.

[0054] Furthermore, the separator supply mechanisms 51 and 61, like the electrode sheet supply mechanisms 31 and 41, are provided with a tension applying mechanism 75. This is the same as that provided in the positive electrode sheet supply mechanism 31, except that it functions to apply tension to the separator sheets 2 and 3.

[0055] Next, the configuration of the winding unit 11 will be described. As shown in Fig. 7, the winding unit 11 includes a turret 12 consisting of two opposing disk-shaped tables rotatably mounted by a drive mechanism (not shown), two winding cores 13 and 14 spaced 180° apart in the rotational direction of the turret 12, two support rollers 15a and 15b positioned approximately 90° apart from the winding cores 13 and 14 in the rotational direction of the turret 12, a separator cutter 16, a pressure roller 17 for pressing down the various sheets 2 to 5 just before winding is completed, and a tape application mechanism 18 for applying a predetermined fixing tape. The winding unit 11 also includes a removal device (not shown) for removing the battery element 1 from the winding cores 13 and 14, located around a removal position P2 (described later).

[0056] The winding cores 13 and 14 are configured to rotate around their own central axes as the rotation axes by a drive mechanism (not shown). The amount of rotation of the winding cores 13 and 14 can be detected by an encoder (not shown), and information relating to the amount of rotation is input from the encoder to the control device 91.

[0057] Additionally, winding cores 13 and 14 are provided so as to be able to protrude into and retract from one of the tables constituting turret 12 along the axial direction of turret 12 (the depth direction of the paper in FIG. 7). When winding cores 13 and 14 protrude from one of the tables, their leading ends are inserted into receiving holes formed in the other table, and are supported in a rotatable state by both tables.

[0058] In addition, the winding cores 13, 14 are each configured to have a non-circular shape in a cross section perpendicular to the rotation axis. In this embodiment, the winding cores 13, 14 have an elliptical shape in a cross section perpendicular to their rotation axis. Because the winding cores 13, 14 have a non-circular cross section, even when the winding cores 13, 14 are rotated at a constant speed, the various sheets 2-5 are supplied to the winding cores 13, 14 while being accelerated and decelerated. Immediately after the start of winding of the various sheets 2-5, the various sheets 2-5 are supplied to the winding cores 13, 14 while being accelerated, and immediately before the end of winding of the various sheets 2-5, the various sheets 2-5 are supplied to the winding cores 13, 14 while being decelerated.

[0059] Furthermore, the winding core 13 (14) has a pair of core pieces 13a, 13b (14a, 14b) that extend along the direction of their own rotation axis (the depth direction of the paper in FIG. 7). A gap 13c (14c) is formed between the core pieces 13a, 13b (14a, 14b). In addition, a chuck mechanism (not shown) is provided at the portion of the winding core 13 (14) that forms the gap 13c (14c) to clamp the separator sheets 2, 3 that are placed in the gap 13c (14c).

[0060] Furthermore, the winding cores 13, 14 are configured to be rotatable between a winding position P1 and a removal position P2 by rotation of the turret 12. The winding position P1 is a position where the winding cores 13, 14 are positioned when winding the various sheets 2 to 5. The removal position P2 is a position where the winding cores 13, 14 are positioned when removing the various sheets 2 to 5 (i.e., the battery element 1) after winding.

[0061] The support rollers 15a and 15b are for hooking and supporting the various sheets 2 to 5 between the cores 13 and 14 that have moved to the removal position P2 and the supply mechanisms 31, 41, 51, and 61.

[0062] The separator cutter 16 is for cutting the separator sheets 2 and 3. The pressure roller 17 is for pressing down the various sheets 2 to 5 that have been wound up.

[0063] The tape application mechanism 18 is for applying fixing tape to the end portions of the separator sheets 2 and 3 after the winding of the various sheets 2 to 5 is completed.

[0064] Next, a description will be given of the roller device 71. As shown in Figures 8 and 9, the roller device 71 includes a transfer roller 711, a position adjustment mechanism 712, and a holder 713. In this embodiment, the position adjustment mechanism 712 constitutes the "position adjustment means."

[0065] As described above, the electrode sheets 4, 5 are hung on the outer peripheral surface of the transfer roller 711, and the transfer roller 711 serves to determine the transport path of the electrode sheets 4, 5. The transfer roller 711 is cylindrical and can freely rotate about a rotation axis RA. In this embodiment, the outer peripheral surface of the transfer roller 711 particularly refers to the surface on which the electrode sheets 4, 5 are hung and which comes into contact with the electrode sheets 4, 5.

[0066] Furthermore, in this embodiment, a plurality of roller devices 71 each having a transfer roller 711 are provided, and at least one of the transfer rollers 711 is adapted to receive the electrode sheets 4, 5 that are transported horizontally or obliquely horizontally at a position immediately upstream of the transfer roller 711 along the transport direction of the electrode sheets 4, 5. At the position immediately upstream of this transfer roller 711, the tabs 4b, 5b are likely to sag due to gravity.

[0067] The position adjustment mechanism 712 is a mechanism for adjusting the position of the transfer roller 711 along the direction of the rotation axis RA (the direction of the thick arrow in FIG. 9) of the transfer roller 711. The position adjustment mechanism 712 includes a shaft portion 7121, a bearing 7122, and a set collar 7123.

[0068] The shaft portion 7121 has a rod shape extending in the direction of the rotation axis RA, and both ends are supported by the holder 713. In this embodiment, the shaft portion 7121 is fixed to the holder 713 and configured to be unable to rotate around the rotation axis RA. However, the shaft portion 7121 may be configured to be rotatable relative to the holder 713 around the rotation axis RA.

[0069] The bearings 7122 are provided between the shaft portion 7121 and the transfer roller 711, and support the transfer roller 711 in a state where it can rotate freely relative to the shaft portion 7121. The bearings 7122 are attached to both ends of the transfer roller 711 in the direction of the rotation axis RA, with their central axes coinciding with the rotation axis RA. Each bearing 7122 includes an outer ring portion 7122a, an inner ring portion 7122b, and rolling elements 7122c.

[0070] The outer ring portion 7122a has an annular shape and is attached to the transfer roller 711 in a state in which relative rotation about the rotation axis RA is restricted.

[0071] The inner ring portion 7122b has an annular shape and is provided inside the outer ring portion 7122a so as to be coaxial with the outer ring portion 7122a. The shaft portion 7121 is inserted into the inner ring portion 7122b, and the bearing 7122 and the transfer roller 711 can be slid along the shaft portion 7121.

[0072] The rolling elements 7122c are spherical, and multiple rolling elements 7122c are provided at equal intervals between the outer ring portion 7122a and the inner ring portion 7122b. The rolling elements 7122c roll to smoothly rotate the outer ring portion 7122a relative to the inner ring portion 7122b, and as a result, the transfer roller 711 can smoothly and freely rotate relative to the shaft portion 7121.

[0073] The set collars 7123 are components that enable switching between a state in which the sliding movement of the bearing 7121 and the transfer roller 711 along the shaft portion 7121 is restricted and a state in which the restriction on the sliding movement is released. The set collars 7123 are annular in shape as a whole, and are provided one on each end of the transfer roller 711 along the direction of the rotation axis RA.

[0074] The set collar 7123 includes a pair of base parts, each of which has a semicircular arc shape, and a screw fastener that connects the two base parts together to form a circular ring shape as a whole. By tightening the screw fasteners and sandwiching the shank 7121 between the pair of base parts, the set collar 7123 is fixed to the shank 7121, and sliding movement of the set collar 7123 along the shank 7121 is restricted. On the other hand, by loosening the screw fasteners and releasing the sandwiching of the shank 7121 between the pair of base parts, sliding movement of the set collar 7123 along the shank 7121 is permitted.

[0075] In this embodiment, with both set collars 7123 in contact with the bearings 7122 (inner ring portions 7122b), the screw fasteners are tightened to fix the set collars 7123 to the shaft portion 7121, thereby restricting the sliding movement of the bearings 7122 and the transfer roller 711 along the shaft portion 7121. During normal times, such as when manufacturing the winding element 1, the sliding movement of the bearings 7122 and the transfer roller 711 along the shaft portion 7121 is restricted.

[0076] On the other hand, by loosening the screw fastener, it becomes possible to slide the bearing 7122 and the transfer roller 711 along the shaft portion 7121. Note that the configuration of the set collar 7123 may be changed as appropriate as long as it is possible to restrict the sliding movement of the bearing 7121 and the transfer roller 711 along the shaft portion 7121 or to release the restriction on the sliding movement.

[0077] The holder 713 supports both ends of the shaft portion 7121, thereby supporting the transfer roller 711 via the shaft portion 7121. In this embodiment, the holder 713 is fixed to a predetermined attachment portion W and is immovable.

[0078] In the present embodiment, the roller device 71 is configured as described above. By releasing the restriction on the sliding movement of the bearing 7122 and the transfer roller 711 and then sliding the bearing 7122 and the transfer roller 711 along the shaft 7121, it is possible to adjust the relative positional relationship between the transfer roller 711 and the electrode sheets 4 and 5 hung on the transfer roller 711. In the present embodiment, adjusting the relative positional relationship between the transfer roller 711 and the electrode sheets 4 and 5 hung on the transfer roller 711 allows the valleys 4c and 5c to extend beyond the widthwise edge 711e of the outer circumferential surface of the transfer roller 711 (see FIG. 10 ). However, in the present embodiment, the relative positional relationship between the transfer roller 711 and the electrode sheets 4 and 5 is set so that more than half (more preferably 80% or more) of the electrode main bodies 4a and 5b along the width direction are hung on the outer circumferential surface of the transfer roller 711.

[0079] Next, the positional relationship maintaining mechanism 72 will be described. As described above, the positional relationship maintaining mechanism 72 is for maintaining the relative positional relationship between the outer circumferential surface of the transfer roller 711 and the electrode sheets 4, 5 hung thereon in an appropriate state. In this embodiment, a positional relationship maintaining mechanism 72 corresponding to one of the multiple transfer rollers 711 in the positive electrode sheet supply mechanism 31 and a positional relationship maintaining mechanism 72 corresponding to one of the multiple transfer rollers 711 in the negative electrode sheet supply mechanism 41 are provided. Of course, multiple positional relationship maintaining mechanisms 72 may be provided along the transport path of each of the electrode sheets 4, 5. For example, a positional relationship maintaining mechanism 72 may be provided for each transfer roller 711.

[0080] 6, the positional relationship maintaining mechanism 72 includes an edge sensor 721 that detects the widthwise position of the electrode sheets 4, 5, a correction unit 722 that corrects the widthwise positional deviation of the electrode sheets 4, 5 based on the position detected by the edge sensor 721, and a meandering correction actuator (not shown) for operating the correction unit 722. Information relating to the widthwise position of the electrode sheets 4, 5 detected by the edge sensor 721 is output to the control device 91. In this embodiment, the edge sensor 721 constitutes the "position detection means," and the correction unit 722 constitutes the "correction means."

[0081] As shown in FIG. 11 , the correction unit 722 includes a pair of upper and lower rollers 722a, 722b, and is configured to be rotatable by the correction actuator around a pivot center α at the top center of the upper roller 722a. The control device 91 controls the correction actuator to rotate the correction unit 722, thereby correcting misalignment of the electrode sheets 4, 5. As a result, it is possible to maintain the state in which the valleys 4c, 5c protrude from the widthwise edge 711e of the outer circumferential surface of the transfer roller 711. In this embodiment, the correction unit 722 also corrects the widthwise misalignment of the electrode sheets 4, 5 based on the position detected by the edge sensor 721 so that the valleys 4c, 5c do not excessively protrude from the widthwise edge 711e of the outer circumferential surface of the transfer roller 711.

[0082] In the winding device 10 configured as described above, the various sheets 2 to 5 are wound as follows. With the separator sheets 2 and 3 stretched across the support rollers 15a (15b), one of the winding cores 13 (14) positioned at winding position P1 is extended from one of the tables of the turret 12, thereby placing the separator sheets 2 and 3 in the gap 13c (14c) of the winding core 13 (14) (see FIG. 12). Next, the chucking mechanism clamps the separator sheets 2 and 3 placed in the gap 13c (14c). Then, the one of the winding cores 13 (14) is rotated a predetermined number of times, thereby winding a predetermined amount of the separator sheets 2 and 3 onto the winding core 13 (14).

[0083] Next, the electrode sheets 4, 5 are sequentially supplied to one of the winding cores 13 (14) by the sheet insertion mechanism 73. Thereafter, the various sheets 2 to 5 are supplied to the winding core 13 (14) while the winding core 13 (14) is rotated, thereby overlapping and winding the various sheets 2 to 5. The winding of the various sheets 2 to 5 is performed in a state where the valley portions 4c, 5c protrude from the widthwise edge portion 711e of the outer peripheral surface of the transfer roller 711.

[0084] Immediately after the start of winding the various sheets 2 to 5, the various sheets 2 to 5 are accelerated and supplied to the winding cores 13, 14. After a certain time has elapsed since the start of winding the various sheets 2 to 5, the winding cores 13, 14 begin to rotate at a constant speed, and the various sheets 2 to 5 are supplied to the winding cores 13, 14 while accelerating and decelerating.

[0085] Thereafter, when a predetermined length of the various sheets 2 to 5 has been wound, the rotation of one of the winding cores 13 (14) is temporarily stopped. When the various sheets 2 to 5 are temporarily stopped, the various sheets 2 to 5 are fed to the winding cores 13, 14 while being decelerated. While the various sheets 2 to 5 are temporarily stopped, the electrode sheets 4, 5 are cut by the sheet cutting cutter 74.

[0086] Thereafter, the rotation of the turret 12 moves one of the winding cores 13 (14) around which the various sheets 2 to 5 are wound to a removal position P2. This results in the separator sheets 2 and 3 being suspended across the support rollers 15a (15b) and the like. The rotation of the turret 12 also moves the other winding core 14 (13) to a winding position P1. The next winding of the various sheets 2 to 5 is performed on this winding core 14 (13).

[0087] Next, a pressure roller 17 is brought close to one of the winding cores 13 (14) arranged at the removal position P2, and the various sheets 2 to 5 are pressed by the pressure roller 17, and the separator sheets 2, 3 are cut by the separator cutter 16 (see Figure 13). After that, one of the winding cores 13 (14) is rotated to completely wind up the various sheets 2 to 5, and the fixing tape is applied to the end portions of the separator sheets 2, 3 by the tape application mechanism 18. This results in a battery element 1 that has been subjected to a winding stop process (see Figure 14). The obtained battery element 1 is removed from the winding core 13 (14) by the removal device.

[0088] As described above in detail, according to this embodiment, the position adjustment mechanism 712 is used to adjust the relative positional relationship between the transfer roller 711 and the electrode sheets 4 and 5, so that the valleys 4c and 5c extend beyond the widthwise edge 711e of the transfer roller 711. That is, when the transfer roller 711 is viewed from a direction perpendicular to the rotation axis RA, the tabs 4b and 5b of the electrode sheets 4 and 5 hung on the transfer roller 711 are entirely positioned outside the outer circumferential surface of the transfer roller 711. Therefore, because the electrode sheets 4 and 5 are supplied to the winding cores 13 and 14 while being accelerated and decelerated, even under conditions in which the tabs 4b and 5b are likely to oscillate, it is possible to more reliably prevent the tabs 4b and 5b from colliding with the outer circumferential surface of the transfer roller 711. As a result, it is possible to suppress the tabs 4b and 5b from jumping up due to a collision with the outer circumferential surface of the transfer roller 711, and ultimately to effectively prevent the tabs 4b and 5b from breaking.

[0089] Furthermore, since the tabs 4b, 5b are prevented from colliding with the outer peripheral surface of the transfer roller 711, the tabs 4b, 5b are prevented from breaking, and the tabs 4b, 5b can be maintained in good condition with less damage, thereby improving the quality of the obtained battery element 1.

[0090] Furthermore, by providing the position adjustment mechanism 712, it becomes possible to accommodate various electrode sheets 4 and 5 with different widths, etc., thereby improving convenience.

[0091] In addition, the positional relationship maintaining mechanism 72 (edge ​​sensor 721 and correction unit 722) can maintain the state in which the valleys 4c, 5c protrude from the widthwise edge 711e of the transfer roller 711. This can more reliably prevent the tabs 4b, 5b from colliding with the outer circumferential surface of the transfer roller 711. This can further enhance the effect of preventing the tabs 4b, 5b from breaking, and can improve the condition of the tabs 4b, 5b.

[0092] Furthermore, in this embodiment, at least one transfer roller 711 is adapted to receive the electrode sheets 4, 5 that are transported horizontally or diagonally horizontally. Therefore, at a position immediately upstream of this transfer roller 711, the tabs 4b, 5b are more likely to sag due to gravity, raising concerns about the tabs 4b, 5b colliding with the transfer roller 711. However, by setting the positional relationship between the electrode sheets 4, 5 and the transfer roller 711 as described above, it is possible to more reliably prevent the tabs 4b, 5b from colliding with the transfer roller 711, even under conditions where the tabs 4b, 5b are more likely to sag.

[0093] Furthermore, in this embodiment, the tabs 4b and 5b are formed by cutting the electrode sheet material 4x and 5x, and the valleys 4c and 5c are formed by the cut surfaces formed by the cutting process. Therefore, the valleys 4c and 5c are likely to become rough (have burrs, etc.), which increases the risk of the tabs 4b and 5b breaking due to the roughened portions running up on the outer peripheral surface of the transfer roller 711. However, by setting the positional relationship between the electrode sheets 4 and 5 and the transfer roller 711 as described above, even if the valleys 4c and 5c are roughened, the roughened portions (e.g., burrs, etc.) can be more reliably prevented from running up on the outer peripheral surface of the transfer roller 711. This further enhances the effectiveness of preventing the tabs 4b and 5b from breaking.

[0094] Furthermore, there is no need to perform processing to remove the rough portions from the valleys 4c and 5c (cut surfaces) in order to prevent the rough portions from riding on the outer peripheral surface of the transfer roller 711. This allows for a reduction in the cost of manufacturing the battery element 1.

[0095] Furthermore, according to this embodiment, the position adjustment mechanism 712 can be realized with a relatively simple configuration, which makes it possible to reduce costs associated with the manufacture and maintenance of the winding device 10 and to make the device more compact.

[0096] In addition, the transfer roller 711 can be slid continuously (analogically) by the position adjustment mechanism 712. This makes it possible to finely adjust the relative positional relationship between the electrode sheets 4, 5 and the transfer roller 711, thereby enabling the relative positional relationship to be set more appropriately.

[0097] The present invention is not limited to the above-described embodiment, and may be implemented as follows: Of course, other applications and modifications not exemplified below are also possible.

[0098] (a) In the above embodiment, the relative positional relationship between the transfer roller 711 and the electrode sheets 4 and 5 hung on the transfer roller 711 can be adjusted by sliding the bearing 7122 and the transfer roller 711 along the shaft 7121. In contrast to this, as shown in Figures 15 and 16, the relative positional relationship between the transfer roller 711 and the electrode sheets 4 and 5 hung on the transfer roller 711 may be adjusted by making the shaft 7141 slidable relative to the holder 7142 along the direction of the rotation axis RA. In other words, the position adjustment mechanism 714 may include a rod-shaped shaft 7141 that supports the transfer roller 711 and a holder 7142 that supports the shaft 7141 in a slidable state along the direction of the rotation axis RA.

[0099] When such a position adjustment mechanism 714 is employed, a set collar 7143 that can be switched between being fixed and released from the shaft portion 7141 may be used, and the set collar 7143 may be configured to be switchable between a state in which the sliding movement of the shaft portion 7141 relative to the holder 7142 along the direction of the rotation axis RA is restricted and a state in which the restriction on the sliding movement is released. The set collar 7143, for example, is fixed to the shaft portion 7141 while in contact with the holder 7142 along the direction of the rotation axis RA, thereby restricting the sliding movement of the shaft portion 7141 relative to the holder 7142 along the direction of the rotation axis RA.

[0100] 17, the relative positional relationship between the transfer roller 711 and the electrode sheets 4 and 5 hung on the transfer roller 711 may be adjustable by making the holder 7151 slidable in the direction of the rotation axis RA with respect to a mechanism base 7152 that functions as a base. That is, the position adjustment mechanism 715 may include a holder 7151 that supports the transfer roller 711 (via a shaft 7153 in this example) and a mechanism base 7152 that supports the holder 7151 in a slidable state along the direction of the rotation axis RA.

[0101] The position adjustment mechanism may be configured by appropriately combining the technical features related to the above-described position adjustment mechanisms 712, 714, and 715. Therefore, for example, a position adjustment mechanism may be configured that can adjust the relative positional relationship between the electrode sheets 4 and 5 and the transfer roller 711 at multiple locations by making the transfer roller 711 slidable along the shaft and making the shaft slidable relative to the holder along the direction of the rotation axis RA.

[0102] (b) The shape of the transfer roller 711 in the above embodiment is merely an example. The shape of the transfer roller 711 may be modified as appropriate as long as it is possible to prevent the tabs 4b and 5b from colliding with the outer circumferential surface of the transfer roller 711. For example, as shown in FIG. 18, the transfer roller 711 may have a tapered portion 711a whose diameter gradually decreases from a widthwise edge 711e on the outer circumferential surface toward the end in the direction of the rotation axis RA. For example, as shown in FIG. 19, the transfer roller 711 may have a relatively small-diameter cylindrical portion 711b that protrudes toward the end in the direction of the rotation axis RA beyond the widthwise edge 711e on the outer circumferential surface. Therefore, the transfer roller 711 may have a portion that can overlap with the tabs 4b and 5b when viewed from a direction perpendicular to the rotation axis RA. However, from the perspective of preventing collision of the tabs 4b and 5b, it is preferable to use a transfer roller 711 that does not have a portion that can overlap with the tabs 4b and 5b when viewed from a direction perpendicular to the rotation axis RA.

[0103] (c) In the above embodiment, the transfer roller 711 is supported in a double-supported state at both end portions along the direction of the rotation axis RA by the shaft portion 7121. In contrast to this, as shown in Fig. 20, the transfer roller 711 may be supported in a cantilevered state by the shaft portion 7153 only at the end portion along the direction of the rotation axis RA that is opposite the end portion on which the tabs 4b and 5b are arranged. In this example, the shaft portion 7153 is supported by the holder 7151, and the holder 7151 is slidable relative to the mechanism base portion 7152 along the direction of the rotation axis RA, thereby enabling adjustment of the relative positional relationship between the transfer roller 711 and the electrode sheets 4 and 5.

[0104] By supporting the transfer roller 711 in a cantilevered state as described above, there is no portion supporting the transfer roller 711 on the side of the transfer roller 711 where the tabs 4b and 5b are arranged, and as a result, the tabs 4b and 5b do not collide with this portion. This more reliably prevents not only the tabs 4b and 5b from colliding with the outer circumferential surface of the transfer roller 711, but also the tabs 4b and 5b from colliding with the portion supporting the transfer roller 711. As a result, breaking of the tabs 4b and 5b can be more effectively prevented.

[0105] (d) In the above embodiment, the tabs 4b, 5b are formed by cutting the electrode sheet material 4x, 5x (so-called formed tabs), but the configuration of the tabs is not limited to this. Therefore, the tabs 4b, 5b may be joined to the electrode main body 4a, 5b by welding (so-called welded tabs), for example. However, welded tabs are often relatively thick, making tab vibration less likely to occur. On the other hand, formed tabs are often thin, making tab vibration more likely to occur. Therefore, the winding device 10 in the above embodiment is particularly effective when the electrode sheets 4, 5 have formed tabs.

[0106] (e) In the above embodiment, the positional relationship maintaining mechanism 72 is provided immediately upstream of the transfer roller 711 along the transport path of the electrode sheets 4 and 5, but the location of the positional relationship maintaining mechanism 72 may be changed as appropriate. Therefore, for example, the positional relationship maintaining mechanism 72 may be provided immediately downstream of the transfer roller 711 along the transport path of the electrode sheets 4 and 5.

[0107] (f) In the above embodiment, the winding unit 11 is configured to include two winding cores 13 and 14, but it may be configured to include one or three or more winding cores.

[0108] The outer peripheral shape of the winding core is not limited to those described in the above embodiment, and may be, for example, a circular or elliptical shape in a cross section perpendicular to the rotation axis of the winding core. Furthermore, the winding core may not have gaps between the core pieces. Additionally, the winding core may be configured such that the electrode sheets 4, 5, etc. are wound around a cylindrical core part provided on the outer periphery of the winding core.

[0109] (g) In the above embodiment, the battery element 1 of a lithium ion battery is manufactured by the winding device 10, but the wound element manufactured by the winding device 10 is not limited to this, and for example, the wound element of an electrolytic capacitor may also be manufactured.

[0110] (h) The materials of the separator sheets 2, 3 and the electrode sheets 4, 5 are not limited to those in the above embodiment and may be changed as appropriate. Of course, the active material applied to the electrode sheets 4, 5 may also be changed. [Explanation of symbols]

[0111] 1...lithium ion battery element (wound element), 2, 3...separator sheet, 4...positive electrode sheet (electrode sheet), 5...negative electrode sheet (electrode sheet), 4a, 5a...electrode main body portion, 4b, 5b...tab, 4c, 5c...valley portion, 10...winding device, 13, 14...winding core, 711...transport roller, 712, 714, 715...position adjustment mechanism (position adjustment means), 721...edge sensor (position detection means), 722...correction portion (correction means), 7121...shaft portion, 7122...bearing, 7123...set collar.

Claims

1. Equipped with a rotatable core, A winding device that supplies a strip-shaped electrode sheet, which includes an electrode main body having an active material on its surface and a plurality of tabs protruding from widthwise edge portions of the electrode main body and provided at intervals along the longitudinal direction of the electrode main body, and a strip-shaped separator sheet made of an insulating material to a winding core while rotating the winding core, and overlaps and winds the electrode sheet and the separator sheet, The electrode sheet is configured to be supplied to the winding core while being accelerated or decelerated, a rotatable transfer roller having an outer circumferential surface on which the electrode sheet is hung and defining a transfer path for the electrode sheet; a position adjusting means for adjusting the position of the transfer roller along the rotation axis of the transfer roller, A winding device characterized in that the position adjustment means adjusts the relative positional relationship between the transfer roller and the electrode sheet hung on the transfer roller, so that a valley portion, which is a widthwise edge portion of the electrode main body portion located between the plurality of tabs, is set to protrude from the widthwise edge portion of the outer surface of the transfer roller.

2. a position detection means for detecting a widthwise position of the electrode sheet hung on the transfer roller; a correction means for correcting a positional deviation of the electrode sheet in the width direction while the electrode sheet is being wound around the winding core, based on the position detected by the position detection means, 2. The winding device according to claim 1, wherein the position detecting means and the correcting means are configured to maintain a state in which the valleys protrude from the widthwise edge of the outer peripheral surface of the transfer roller.

3. 2. The winding device according to claim 1, wherein the electrode sheet is wound around the transfer roller at a position immediately upstream of the transfer roller along the direction of transport of the electrode sheet, the electrode sheet being transported horizontally or obliquely horizontally.

4. the tab is formed by cutting a strip-shaped electrode sheet material having an active material on its surface, the valley portion is constituted by a cut surface formed by the cutting process, 2. The winding device according to claim 1, wherein the winding core is used for winding the electrode sheet, the valley portion of which is formed by the cut surface.

5. 2. The winding device according to claim 1, wherein the transfer roller is supported in a cantilevered state only at one end along the rotation axis direction, the end opposite to the side on which the tab is arranged.

6. The position adjusting means is a rod-shaped shaft portion extending in the direction of the rotation axis; a bearing attached to the transfer roller with the shaft portion inserted therethrough, and supporting the transfer roller in a freely rotatable state relative to the shaft portion; a set collar that can be switched between a state in which sliding movement of the bearing along the shaft portion is restricted and a state in which restriction of the sliding movement is released, 2. The winding device according to claim 1, wherein the relative positional relationship between the transfer roller and the electrode sheet hung on the transfer roller can be adjusted by sliding the bearing along the shaft portion.

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