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 produced 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 in a superimposed state with a separator sheet made of an insulating material interposed therebetween.

[0003] A known electrode sheet has an electrode body having an active material on its surface and tabs protruding from the widthwise edge of the electrode body. The tabs are provided at intervals along the longitudinal direction of the electrode body.

[0004] A winding device for manufacturing a wound element is known that 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 a freely rotatable transport roller on which the electrode sheet or the like is hung, and the transport roller has a role of determining 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 deal with such tab bending, a technique 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, etc.). 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 bending. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] JP 2016-35892 A Summary of the Invention [Problem to be solved by the invention]

[0007] However, after extensive research, the inventors of the present invention have discovered the following factors that cause the tab to break.

[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 tab to swing along the thickness direction of the electrode sheet. Then, when the swinging tab collides with the outer circumferential surface of the transport roller, the tab jumps up, and as a result, the tab breaks.

[0009] In this regard, the technology described in the above Patent Document 1 does nothing to solve the problem of the tab colliding with the outer circumferential surface of the transfer roller and being thrown up. On the contrary, the thrown up tab may collide with the deformation prevention member, causing deformation or damage to 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. Note that, as necessary, the specific effects of the corresponding means will be added.

[0012] Means 1. Equipped with a rotatable core, A winding device that supplies a strip-shaped electrode sheet having an electrode main body having an active material on a surface thereof and a plurality of tabs protruding from widthwise edges of the electrode main body and provided at intervals along a longitudinal direction of the electrode main body, and a strip-shaped separator sheet made of an insulating material to the winding core while rotating the winding core, the winding core overlapping and winding 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 a position of the transfer roller along a rotation axis direction of the transfer roller, A winding device characterized in that by using the position adjustment means to adjust the relative positional relationship between the transfer roller and the electrode sheet hung on the transfer roller, a valley portion, which is a widthwise edge portion of the electrode main body portion located between a plurality of the tabs, is set to extend beyond the widthwise edge portion of the outer peripheral surface of the transfer roller.

[0013] According to the above-mentioned means 1, the electrode sheet is supplied to the core while being accelerated and decelerated. Therefore, the tab vibrates due to vibration or resonance caused by the acceleration or deceleration of the electrode sheet, and as a result, the tab may collide with the outer circumferential surface of the transfer roller, 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. The relative positional relationship between the transfer roller and the electrode sheet is adjusted using this position adjustment means, so that the valley portion, which is the widthwise edge portion of the electrode main body portion located between the multiple tabs, is set to protrude from the widthwise edge portion of the outer circumferential surface of the transfer roller. That is, 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 at a position deviated from the outer circumferential surface of the transfer roller. Therefore, even if the tab vibrates, the tab can be more reliably prevented from colliding with the outer circumferential surface of the transfer roller. As a result, it is possible to suppress the tab from jumping up due to the collision with the outer circumferential surface of the transfer roller, and thus it is possible to effectively prevent the tab from breaking.

[0015] In addition, since the collision of the tab with the outer circumferential surface of the transport roller is prevented, the tab can be kept in good condition with less damage, and the quality of the wound element obtained can be improved.

[0016] Furthermore, by providing a position adjustment means, it becomes possible to accommodate various electrode sheets having 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 transport roller; a correction means for correcting a positional deviation of the electrode sheet in a width direction during winding of the electrode sheet around the winding core based on the position detected by the position detection means, The winding device described in Means 1 is characterized in that the position detection means and the correction means are configured to maintain a state in which the valley portion protrudes from the width direction edge portion of the outer circumferential 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 circumferential surface of the transfer roller. Therefore, it is possible to more reliably prevent the tab from colliding with the outer circumferential surface of the transfer roller. This can further enhance the effect of preventing the tab from breaking and improve the condition of the tab.

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

[0020] According to the above-mentioned Means 3, the electrode sheet is transported horizontally or obliquely 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 circumferential 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 transport roller even under conditions that tend to cause the tab to sag 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 transported horizontally or obliquely horizontally is hung on the transport roller at a position immediately upstream of the roller.

[0022] Means 4. The tab is formed by cutting a belt-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, 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 means 4, the tab is formed by subjecting the electrode sheet material to a cutting process using a laser, a die, or the like, and the valley portion is constituted by a cut surface formed by the cutting process. Therefore, the valley portion is likely to be in a rough state (a state having burrs, etc.).

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

[0025] In addition, there is no need to perform a process to remove the rough portions from the valleys (cut surfaces) in order to prevent the rough portions from riding on the outer circumferential surface of the transfer roller, which can reduce 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 manner 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 means 5, the transfer roller is supported in a cantilevered state only at the end opposite to the side where the tab is arranged. Therefore, there is no part supporting the transfer roller on the side where the tab is arranged, and therefore the tab does not collide with the part. This makes it possible to more reliably prevent not only the tab from colliding with the outer circumferential surface of the transfer roller, but also with the part supporting the transfer roller. As a result, it is possible to more effectively prevent the tab from breaking.

[0028] Means 6. The position adjustment 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 the sliding movement of the bearing along the shaft portion is restricted and a state in which the restriction of the sliding movement is released, The winding device described in Means 1 is characterized in 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 the manufacture and maintenance of the winding device and to reduce the size of the device.

[0030] Furthermore, according to the above-mentioned means 6, the transport roller can be slid continuously (analogly). Therefore, it is possible to finely adjust the relative positional relationship between the electrode sheet and the transport roller, and thus the relative positional relationship can be set more appropriately.

[0031] In addition, the technical matters related to the above-mentioned means may be combined as appropriate. For example, the technical matters related to the above-mentioned means 2 may be combined with the technical matters related to the above-mentioned means 5. [Brief description of the drawings]

[0032] [Figure 1] FIG. 2 is a perspective view showing a schematic configuration of a battery element. [Diagram 2] FIG. 2 is a plan view showing a schematic configuration of a positive electrode sheet. [Diagram 3] FIG. 2 is a plan view showing a schematic configuration of a negative electrode sheet. [Figure 4] FIG. 2 is a schematic plan view showing how a cutting process is performed on a positive electrode sheet material to form a tab of the positive electrode sheet. [Diagram 5] FIG. 13 is a schematic plan view showing a cutting process being performed on a negative electrode sheet material to form a tab of the negative electrode sheet. [Figure 6] FIG. 2 is a schematic diagram of a winding device. [Figure 7] FIG. 2 is a schematic configuration diagram of a winding section. [Figure 8] FIG. [Figure 9] 9 is a cross-sectional view taken along line JJ in FIG. 8. [Figure 10] 4 is a schematic plan view showing the positional relationship between a valley portion of an electrode sheet and a width direction edge portion of an outer circumferential surface of a transfer roller. FIG. [Figure 11] FIG. [Figure 12] FIG. 13 is a schematic configuration diagram of a winding section when a separator sheet is disposed in a gap in a winding core. [Figure 13] FIG. 13 is a schematic diagram of a winding section when cutting a separator sheet. [Figure 14] 1 is a schematic diagram of a winding section when winding of an electrode sheet or the like is completed; FIG. [Figure 15] 13 is a schematic perspective view of a roller device and the like illustrating a position adjustment mechanism according to another embodiment. FIG. [Figure 16] 16 is a cross-sectional view taken along line KK in FIG. 15. [Figure 17] 13 is a schematic perspective view of a roller device illustrating a position adjustment mechanism according to another embodiment. FIG. [Figure 18] FIG. 11 is a partially cutaway front view of a roller device showing a transport roller in another embodiment. [Figure 19] FIG. 11 is a partially cutaway front view of a roller device showing a transport roller in another embodiment. [Figure 20] FIG. 13 is a schematic perspective view of a roller device and the like showing a transport roller supported in a cantilevered state in another embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0033] An embodiment will be described below with reference to the drawings. First, the configuration 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 superimposed 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. In the following, for convenience of explanation, 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, 3 are each in the form of a strip having the same width, and are made of an insulator such as polypropylene (PP) to prevent the different electrode sheets 4, 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, and for example, an aluminum foil sheet is used for the positive electrode sheet 4, and for example, a copper foil sheet is 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 portion 4a, 5a and a tab 4b, 5b.

[0038] The electrode main body parts 4a, 5a have approximately the same width as the separator sheets 2, 3, and the front and back surfaces of the electrode main body parts 4a, 5a are coated with active material. The electrode main body part 4a of the positive electrode sheet 4 is coated with a positive electrode active material (e.g., lithium manganate particles, etc.) (the coated portion of the active material is shown by a dot pattern in Figs. 2, 3, etc.). The electrode main body part 5a of the negative electrode sheet 5 is coated with a negative electrode active material (e.g., activated carbon, etc.). Ion exchange is possible between the positive electrode sheet 4 and the negative electrode sheet 5 through the active material. Although Figs. 2 and 3 show a configuration in which the active material is not coated on a part (e.g., the widthwise edge part) of the electrode main body parts 4a, 5a, the active material may be coated on the entire area of ​​the electrode main body parts 4a, 5a.

[0039] The tabs 4b, 5b protrude from the widthwise edge of the electrode main body 4a, 5a, and are provided at intervals along the longitudinal direction of the electrode main body 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 edge of the same side of the electrode main body 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, cutting the positive electrode sheet material 4x along the two-dot chain line 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 body portions 4a and 5b extending along the longitudinal direction of the electrode sheets 4 and 5, and the valley portions 4c and 5c located between the tabs 4b and 5b, are formed by the cut surfaces formed by the cutting process. The valley portions 4c and 5c formed by the cut surfaces may have burrs or the like and may be in a rough state. In this embodiment, the positive electrode sheet material 4x and the negative electrode sheet material 5x each correspond to an "electrode sheet material".

[0041] When obtaining a lithium ion battery, the battery element 1 is disposed in a cylindrical metallic 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 part (not shown), and the bundled tabs 5b are connected to a negative electrode terminal part (not shown), and the two terminal parts are provided to close both end openings of the battery container, thereby obtaining a lithium ion battery.

[0042] Next, a winding device 10 for manufacturing the battery element 1 will be described. 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 in 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 original 32 in which the positive electrode sheet 4 is wound in a roll shape. The positive electrode sheet original 32 is supported so as to be freely rotatable, and the positive electrode sheet 4 is appropriately pulled out from there.

[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 hung on its outer circumferential surface and including a transfer roller 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 supplying the positive electrode sheet 4 to the winding unit 11 while holding it.

[0048] The sheet cutting cutter 74 is for cutting the positive electrode sheet 4. The cutting of the positive electrode sheet 4 is performed in a state in which the positive electrode sheet 4 is gripped by the sheet insertion mechanism 73. In addition, the sheet cutting cutter 74 can be separated from the conveyance path of the positive electrode sheet 4 so as not to impede the supply of the positive electrode sheet 4 by the sheet insertion mechanism 73.

[0049] The tension applying mechanism 75 is for applying tension to the positive electrode sheet 4, and includes a plurality of rollers (e.g., dancer rollers, etc.). The operation of these rollers is controlled by the control device 91, so that the tension applied from the tension applying mechanism 75 to the positive electrode sheet 4 can be adjusted. In this embodiment, the tension applying mechanism 75 is configured to always apply a constant tension to the positive electrode sheet 4. Note that, in terms of the relative positional relationship with the positive electrode sheet 4, the rollers constituting the tension applying mechanism 75 may be configured similarly to the transport roller 711.

[0050] The buffer mechanism 76 has, for example, a pair of driven rollers and a lift roller disposed between the rollers so as to be vertically displaceable, and serves to temporarily store the positive electrode sheet 4. Note that, in terms of the relative positional relationship with the positive electrode sheet 4, the rollers constituting the buffer mechanism 76 may be configured similarly to the transfer roller 711.

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

[0052] Further, in the middle of the transport path of the negative electrode sheet 5 from the negative electrode sheet raw material 42 to the winding section 11, a roller device 71, a positional relationship maintaining mechanism 72, a sheet insertion mechanism 73, a sheet cutting cutter 74, a tension applying mechanism 75, a buffer mechanism 76, and the like are provided, similar to the transport path of the positive electrode sheet 4. These are similar to those provided in the transport path of 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 original rolls 52, 62 each formed by winding up the separator sheets 2, 3 in a roll shape. The separator original rolls 52, 62 are supported so as to be freely rotatable, and the separator sheets 2, 3 are appropriately pulled out from them.

[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 similar to the one provided in the positive electrode sheet supply mechanism 31, except that it functions for 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 provided by a driving mechanism (not shown), two winding cores 13, 14 provided at 180° intervals in the rotation direction of the turret 12, two support rollers 15a, 15b provided at positions shifted by approximately 90° from the winding cores 13, 14 in the rotation direction of the turret 12, a separator cutter 16, a pressing roller 17 for pressing the various sheets 2 to 5 just before the winding is completed, and a tape application mechanism 18 for applying a predetermined fixing tape. In addition, the winding unit 11 includes a removal device (not shown) for removing the battery element 1 from the winding cores 13, 14 in the periphery of a removal position P2 described later.

[0056] The winding cores 13 and 14 are adapted to take up the various sheets 2 to 5 on their respective outer peripheries and are configured to be rotatable about 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 grasped by an encoder (not shown), and information relating to the amount of rotation is input from the encoder to the control device 91.

[0057] The winding cores 13 and 14 are provided so as to be able to protrude into and retract from one of the tables constituting the turret 12 along the axial direction of the turret 12 (the depth direction of the paper in FIG. 7). When the winding cores 13 and 14 protrude from one of the tables, their tips 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 and 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 and 14 have an elliptical shape in a cross section perpendicular to their own rotation axis. Since the winding cores 13 and 14 have a non-circular cross section, even when the winding cores 13 and 14 are rotated at a constant speed, the various sheets 2 to 5 are supplied to the winding cores 13 and 14 while accelerating and decelerating. Immediately after the start of winding the various sheets 2 to 5, the various sheets 2 to 5 are supplied to the winding cores 13 and 14 while accelerating, and immediately before the end of winding the various sheets 2 to 5, the various sheets 2 to 5 are supplied to the winding cores 13 and 14 while decelerating.

[0059] Furthermore, the winding core 13 (14) has a pair of core pieces 13a, 13b (14a, 14b) each extending along its own rotation axis direction (depth direction in the plane of the paper in FIG. 7). A gap 13c (14c) is formed between the core pieces 13a, 13b (14a, 14b). A chuck mechanism (not shown) is provided at a portion of the winding core 13 (14) that forms the gap 13c (14c) to clamp the separator sheets 2, 3 arranged 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 2-5. The removal position P2 is a position where the winding cores 13, 14 are positioned when removing the various sheets 2-5 (i.e., the battery element 1) after winding.

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

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

[0063] The tape application mechanism 18 is for applying a fixing tape to the end portions of the separator sheets 2, 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 has a role of determining a transport path for 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] 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 transferred horizontally or obliquely horizontally at a position immediately upstream of the transfer roller 711 along the transfer direction of the electrode sheets 4, 5. At the position immediately upstream of the 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 not to rotate around the rotation axis RA. Note that 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 freely rotatable state 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, one on each side, 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 a rolling element 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 coaxially 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 a plurality of them 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 be smoothly and freely rotated relative to the shaft portion 7121.

[0073] The set collar 7123 is a component for enabling 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 collar 7123 has an annular shape as a whole, and is provided on each end side 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 having a semicircular arc shape, and a screw fastener that connects the two base parts together to form an annular shape as a whole. The screw fastener is then tightened to sandwich the shaft portion 7121 between the pair of base parts, thereby fixing the set collar 7123 to the shaft portion 7121 and restricting the sliding movement of the set collar 7123 along the shaft portion 7121. On the other hand, the screw fastener is loosened to release the sandwiching of the shaft portion 7121 between the pair of base parts, thereby allowing the set collar 7123 to slide along the shaft portion 7121.

[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 appropriately changed 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, etc. In this embodiment, the holder 713 is fixed to a predetermined attachment portion W and is immovable.

[0078] The roller device 71 is configured as described above, and in this embodiment, the sliding movement restriction of the bearing 7122 and the transport roller 711 is released, and then the bearing 7122 and the transport roller 711 are slid along the shaft portion 7121, thereby making it possible to adjust the relative positional relationship between the transport roller 711 and the electrode sheets 4 and 5 hung on the transport roller 711. In this embodiment, the valleys 4c and 5c are set to protrude from the width direction edge portion 711e of the outer circumferential surface of the transport roller 711 by adjusting the relative positional relationship between the transport roller 711 and the electrode sheets 4 and 5 hung on the transport roller 711 (see FIG. 10). However, in this embodiment, the relative positional relationship between the transport roller 711 and the electrode sheets 4 and 5 is set so that more than half (more preferably more than 80%) of the electrode main bodies 4a and 5b along the width direction are hung on the outer circumferential surface of the transport 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, a plurality of 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 around a pivot center α at the top center of the upper roller 722a by the correction actuator. The control device 91 controls the correction actuator, and the correction unit 722 rotates to correct the positional deviation 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 portion 711e of the outer circumferential surface of the transfer roller 711. In this embodiment, the correction unit 722 also corrects the positional deviation in the width direction 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 portion 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. That is, with the separator sheets 2 and 3 stretched across the support rollers 15a (15b) and the like, one of the winding cores 13 (14) arranged at the winding position P1 is protruded from one of the tables in the turret 12 to arrange the separator sheets 2 and 3 in the gap 13c (14c) of the winding core 13 (14) (see FIG. 12). Next, the separator sheets 2 and 3 arranged in the gap 13c (14c) are clamped by the chuck mechanism. Then, one of the winding cores 13 (14) is rotated a predetermined number of times to wind up a predetermined amount of the separator sheets 2 and 3 around 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 2-5 are supplied to the winding core 13 (14) while the winding core 13 (14) is rotated, thereby overlapping and winding the various sheets 2-5. The winding of the various sheets 2-5 is performed in a state where the valleys 4c, 5c protrude from the width direction edge portion 711e of the outer circumferential surface of the transfer roller 711.

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

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

[0087] Next, the 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 FIG. 13). After that, the 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 FIG. 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 are set to protrude from the widthwise edge portion 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 set to be entirely located at a position outside the outer circumferential surface of the transfer roller 711. Therefore, since the electrode sheets 4 and 5 are supplied to the cores 13 and 14 while being accelerated and decelerated, it is possible to more reliably prevent the tabs 4b and 5b from colliding with the outer circumferential surface of the transfer roller 711 due to the oscillation of the tabs 4b and 5b even under conditions in which the tabs 4b and 5b are likely to oscillate. As a result, it is possible to suppress the tabs 4b and 5b from jumping up due to the collision with the outer circumferential surface of the transfer roller 711, and thus it is possible to effectively prevent the tabs 4b and 5b from breaking.

[0089] In addition, since the tabs 4b, 5b are prevented from colliding with the outer circumferential 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. Therefore, the quality of the obtained battery element 1 can be improved.

[0090] Furthermore, by providing the position adjustment mechanism 712, it becomes possible to accommodate various electrode sheets 4, 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] In this embodiment, the electrode sheets 4, 5 transported horizontally or obliquely horizontally are hung on at least one of the transport rollers 711. Therefore, at a position immediately upstream of the transport roller 711, the tabs 4b, 5b are likely to sag due to gravity, and collision of the tabs 4b, 5b with the transport roller 711 is of greater concern. However, by setting the positional relationship between the electrode sheets 4, 5 and the transport roller 711 as described above, it is possible to more reliably prevent the tabs 4b, 5b from colliding with the transport roller 711 even under conditions where the tabs 4b, 5b are likely to sag.

[0093] Furthermore, in this embodiment, the tabs 4b, 5b are formed by cutting the electrode sheet material 4x, 5x, and the valleys 4c, 5c are formed by the cut surfaces formed by the cutting process. Therefore, the valleys 4c, 5c are likely to become rough (having burrs, etc.), and there is a greater concern that the rough parts will ride up on the outer circumferential surface of the transfer roller 711 and cause the tabs 4b, 5b to break. However, by setting the positional relationship between the electrode sheets 4, 5 and the transfer roller 711 as described above, even if the valleys 4c, 5c are rough, the rough parts (e.g., burrs, etc.) can be more reliably prevented from riding up on the outer circumferential surface of the transfer roller 711. This can further enhance the effect of preventing the tabs 4b, 5b from breaking.

[0094] Also, there is no need to perform processing for removing the rough portions of the valleys 4c, 5c (cut surfaces) in order to prevent the rough portions from riding on the outer circumferential surface of the transfer roller 711. This makes it possible to reduce 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 reduce the size of the device.

[0096] In addition, the transfer roller 711 can be slid continuously (analog-like) 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, and thus to more appropriately set the relative positional relationship.

[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, 5 hung on the transfer roller 711 can be adjusted by sliding the bearing 7122 and the transfer roller 711 along the shaft portion 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, 5 hung on the transfer roller 711 may be adjusted by making the shaft portion 7141 slidable relative to the holder 7142 along the direction of the rotation axis RA. That is, the position adjustment mechanism 714 may include a rod-shaped shaft portion 7141 that supports the transfer roller 711 and a holder 7142 that supports the shaft portion 7141 in a state where it can slide along the direction of the rotation axis RA.

[0099] When such a position adjustment mechanism 714 is employed, a set collar 7143 capable of switching between being fixed to and released from the shaft portion 7141 may be used to switch 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 restricts the sliding movement of the shaft portion 7141 relative to the holder 7142 along the direction of the rotation axis RA by being fixed to the shaft portion 7141 while being in contact with the holder 7142 along the direction of the rotation axis RA, for example.

[0100] 17, the holder 7151 may be slidably moved in the direction of the rotation axis RA with respect to a mechanism base 7152 functioning as a base, thereby making it possible to adjust the relative positional relationship between the transfer roller 711 and the electrode sheets 4, 5 hung on the transfer roller 711. 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 matters related to the above-mentioned position adjustment mechanisms 712, 714, and 715. Therefore, for example, a position adjustment mechanism may be configured in which the relative positional relationship between the electrode sheets 4 and 5 and the transfer roller 711 can be adjusted at multiple points by making the transfer roller 711 slidable along the shaft portion and making the shaft portion 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 an example, and the shape of the transfer roller 711 may be changed 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. Therefore, for example, as shown in FIG. 18, the transfer roller 711 may have a tapered portion 711a that gradually reduces in diameter from a widthwise edge portion 711e on the outer circumferential surface toward the end in the direction of the rotation axis RA. Also, 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 from the widthwise edge portion 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 viewpoint of preventing the tabs 4b and 5b from colliding with each other, 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 ends along the direction of the rotation axis RA by the shaft portion 7121. In contrast, as shown in Fig. 20, the transfer roller 711 may be supported in a cantilevered state only at an end along the direction of the rotation axis RA, which is an end opposite to the side where the tabs 4b and 5b are arranged, by the shaft portion 7153. 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 making it possible to adjust 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 therefore the tabs 4b and 5b do not collide with the portion. This makes it possible to more reliably prevent 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, it is possible to more effectively prevent the tabs 4b and 5b from breaking.

[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, and the tabs are relatively unlikely to swing. On the other hand, formed tabs are often thin, and the tabs are very likely to swing. 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, 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, 5.

[0107] (f) In the above embodiment, the winding unit 11 is configured to include two winding cores 13, 14, but may be configured to include one winding core 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 for example, the outer peripheral surface of the winding core may be circular or elliptical 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. In addition, the electrode sheets 4, 5, etc. may be 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, a wound element of an electrolytic capacitor, etc. may 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 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, 4b, 5b...tab, 4c, 5c...valley, 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 section (correction means), 7121...shaft, 7122...bearing, 7123...set collar.

Claims

1. A rotatable core is provided, A winding device that supplies a strip-shaped electrode sheet having an electrode main body having an active material on a surface thereof and a plurality of tabs protruding from widthwise edges of the electrode main body and provided at intervals along a longitudinal direction of the electrode main body, and a strip-shaped separator sheet made of an insulating material to the winding core while rotating the winding core, the winding core overlapping and winding 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 a position of the transfer roller along a rotation axis direction of the transfer roller, A winding device characterized in that by using the position adjustment means to adjust the relative positional relationship between the transfer roller and the electrode sheet hung on the transfer roller, a valley portion, which is a widthwise edge portion of the electrode main body portion located between a plurality of the tabs, is set to extend beyond the widthwise edge portion of the outer peripheral surface of the transfer roller.

2. a position detection means for detecting a position in a width direction of the electrode sheet hung on the transfer roller; a correction means for correcting a positional deviation of the electrode sheet in a width direction during winding of the electrode sheet 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 capable of maintaining a state in which the valley portion protrudes from an edge portion in the width direction of the outer circumferential surface of the transfer roller.

3. 2. The winding device according to claim 1, wherein the electrode sheet is hung on the transport roller at a position immediately upstream of the transport roller in the transport direction of the electrode sheet, the electrode sheet being transported in a horizontal or oblique horizontal direction.

4. the tab is formed by cutting a strip-shaped electrode sheet material having an active material on a surface thereof, 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 being formed by the cut surface.

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

6. The position adjustment 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 the sliding movement of the bearing along the shaft portion is restricted and a state in which the 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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