JP2013022527A - Coating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a coating apparatus intended to improve productivity by increasing the coating speed while making an attempt to improve coating quality.SOLUTION: The apparatus intermittently applies an active material in the form of slurry ejected from a coating head 3 onto a current collector, which is a base material. The coating head 3 includes an eject port 16 in the shape of a slit formed into an opening in a head body 3a, a valve chamber 17 formed at a deeper side of the eject port 16 of the head body 3a, and a cam shaft 20 accommodated and arranged rotatably in the valve chamber 17. The eject port 16 is configured to be closed directly by a cam lob 22 at a rate of one rotation per rotation of the cam shaft 20.

Description

  The present invention relates to a coating apparatus for intermittently applying a slurry-like substance on a substrate.

  For example, in a manufacturing process of a lithium ion secondary battery, an active material layer is formed by applying and drying a slurry-like active material on a foil-like current collector as a base material. For the application of the active material, a coating device called a coater is used. For example, in the techniques described in Patent Documents 1 and 2, a shutter is provided in the paint storage part of the application head whose lower surface is opened in a slit shape as a paint discharge part. A member is provided, and the slit-like opening is opened and closed by opening and closing the shutter member, and the paint is intermittently discharged and applied to the substrate in a so-called free fall state.

Japanese Patent Laid-Open No. 11-10061 Japanese Patent Laid-Open No. 11-197572

  However, in the techniques described in Patent Documents 1 and 2, there is a concern that the tip of the shutter member may be worn by an impact at the time of frequent closing operation, which improves the durability of the shutter member, which is the most important in terms of function. In addition, there is a problem that the coating film thickness is not uniform due to insufficient parallelism in the coating width direction of the shutter member, and the coating quality cannot be improved.

  In addition, in the techniques described in Patent Documents 1 and 2, not only paint is intermittently discharged in a so-called free fall state, but also the rotation of the servo motor is converted into the linear reciprocating motion of the shutter member by the linear motion conversion unit. Since the slit-shaped opening is opened and closed by conversion, there is a limit in increasing the coating speed and there is a problem that improvement in productivity cannot be expected.

  The present invention has been made paying attention to such problems, and is intended to provide a coating apparatus that improves the productivity by increasing the coating speed while improving the coating quality. is there.

  The present invention includes a coating head that is disposed close to a substrate to which a slurry-like substance is to be applied and is pumped from the slurry-like substance supply source, and relatively moves the substrate and the coating head. In the coating apparatus, the slurry-like substance is discharged from the coating head and applied intermittently on the substrate.

  In this case, the coating head includes a slit-like discharge opening formed in the head main body, and a cam member that is rotatably accommodated and disposed on the back side of the discharge outlet in the head main body. The discharge port is closed directly or indirectly at a rate of once per rotation of the cam member.

  According to the present invention, the cam member in the head body of the coating head to which the slurry-like substance is pumped from the slurry-like substance supply source rotates, and the discharge port is set once per rotation of the cam member. Since it closes directly or indirectly, the coating state of the slurry-like substance is extremely stabilized, and the coating quality can be improved. In addition, since the application speed can be sufficiently followed, productivity can be improved.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows the 1st Embodiment of this invention. In the manufacturing process of a lithium ion secondary battery, the outline outline of the whole apparatus which apply | coats a slurry-like active material intermittently on a foil-like collector. Figure. FIG. 2 is an enlarged explanatory view of a main part of FIG. 1. It is a figure which shows the detail of the coating head in FIG. 2, and is sectional explanatory drawing which follows the BB line of FIG. It is a figure which shows the detail of the coating head in FIG. 2, and is sectional explanatory drawing which follows the AA line of FIG. The principal part enlarged view of FIG. The principal part disassembled perspective view of the coating head shown to FIG. The time chart which shows the coating shape by a coating head, and the opening / closing timing of each of a coating valve, a return valve, and a camshaft. Explanatory drawing of the drive system for synchronizing each opening / closing timing of a coating valve, a return valve, and a camshaft. Sectional explanatory drawing which shows the modification of FIG. 5 as the 2nd Embodiment of this invention. Sectional explanatory drawing which shows the modification of FIG. 5 as the 3rd Embodiment of this invention.

  1 and the following drawings show a more specific first embodiment for carrying out the present invention. For example, in a manufacturing process of a lithium ion secondary battery, a slurry shape is formed on a foil-like current collector as a base material. In this example, the active material is intermittently applied to form a positive electrode or a negative electrode with a coating film of the active material. In particular, FIG. 1 shows a schematic structure of the entire system including the coating apparatus, and FIG. 2 shows details of a main part of FIG. 1 centering on the coating apparatus.

  1 schematically includes a coating roll 4, a take-up roll 2, a coating device 4 having a coating head 3 as main elements, and a drying unit 5. The current collector W as a base material drawn out from the feed roll unit 1 is guided so as to be wound around the backup roll 6 and the guide rollers 7 to 9. Then, with the winding state, the current collector W travels at a predetermined speed while being applied with a predetermined tension, and is wound around the winding roll unit 2.

  The coating head 3 of the coating apparatus 4 is disposed so as to be close to the portion where the current collector W is wound by the backup roll 6. In the process in which the current collector W travels while being backed up by the backup roll 6, a slurry-like active material as a slurry-like material is discharged from a discharge port of the coating head 3 to be described later and applied to the current collector W. . The active material applied to the current collector W is dried in the process of passing through the drying unit 5 and fixed to the current collector W as a coating film of the active material layer, and finally the winding roll unit together with the current collector W 2 is wound up.

  FIG. 2 shows details of the coating apparatus 4 of FIG. In addition to the coating head 3, the coating apparatus 4 has a slurry tank 10 as a slurry-like material supply source in which a slurry-like active material is stored. The coating head 3 has a slurry-like shape in the slurry tank 10. The active material is pumped by the pump 11. In the supply path 12 connecting the slurry tank 10 and the coating head 3, a coating valve 13 as a main opening / closing valve is provided downstream of the pump 11, and a return valve 14 is provided in parallel with the pump 11. It is.

  The coating valve 13 and the return valve 14 are reversely operated in synchronization with each other. If the coating valve 13 is open, the return valve 14 is closed, and conversely, the coating valve 13 is closed. If there is, the return valve 14 is set to be open. This is to return the active material pumped from the pump 11 to the slurry tank 10 by opening the return valve 14 instead when the coating valve 13 is closed during the continuous operation of the pump 11. As will be described later, the discharge port on the coating head 3 side is also opened and closed in synchronization with the opening and closing of the coating valve 13. The supply of the active material from the pump 11 to the coating head 3 is performed at a pressure of about 0.1 to 1.0 MPa, for example, depending on the characteristics of the slurry-like active material and the application conditions.

  Then, in the process of continuously running while the current collector W is wound around the backup roll 6, the slurry-like active material P as the slurry-like substance is discharged from the discharge port of the coating head 3, The slurry-like active material P is intermittently applied to the current collector W at a predetermined interval and a predetermined film thickness by the coating head 3.

  3 to 6 show details of the coating head 3 in the coating apparatus 4.

  As shown in FIGS. 3 and 4, the coating head 3 has a cross-sectional shape of a trapezoidal shape and a pair of long divided pieces 15 a and 15 b that are fastened together with bolts or the like not shown in the drawing. A head main body 3a is formed, and a slit-like long discharge port 16 is formed in the front end portion of the head main body 3a along the longitudinal direction. Further, a valve chamber 17 having a circular cross section communicating with the discharge port 16 is formed on the back side of the discharge port 16, and further, a communication path to the valve chamber 17 on the back side of the valve chamber 17. A chamber portion 19 having a larger cross-sectional area than the valve chamber 17 is formed while communicating with each other. As described above with reference to FIG. 2, since the slurry-like active material is supplied from the slurry tank 10 to the chamber part 19 via the supply path 12, the supply path for both the chamber part 19 and the valve chamber 17 is provided. 12 will function as a part. As shown in FIG. 5 which is an enlarged view of FIG. 3, both the discharge port 16 and the communication path 18 are located on the extended line of the diameter of the valve chamber 17.

  A camshaft 20 as a cam member is accommodated in the valve chamber 17 along the longitudinal direction. The camshaft 20 is provided with a shaft portion 21 and a cam lobe 22 having a predetermined profile shape, and the shaft portion 21 protruding from both ends of the cam lobe 22 is rotatably supported on the head body 3a. The bearing portion of the camshaft 20 is sealed by a seal member 23 as shown in FIG. 6, and a timing gear 24 is fixed by a nut 25 at the protruding end of the shaft portion 21 from the head body 3a. Then, the camshaft 20 is rotationally driven with a timing chain or timing belt (not shown) wound around the timing gear 24 as an input side.

  Here, as shown in FIG. 5, the shaft portion 21 of the camshaft 20 is eccentric with respect to the center of the valve chamber 17, and the cam lobe 22 itself also serves as a valve body. Only at a position where 22 a coincides with the discharge port 16, the discharge port 16 is closed in contact with the inner wall surface of the valve chamber 17. That is, the nose portion 22a of the cam lobe 22 is set so as to directly close the discharge port 16 at a rate of once per rotation of the camshaft 20, and as is apparent from FIG. Closed corresponding to the opening width of the discharge port 16 in the circumferential direction of the valve chamber 17 rather than the open section during one rotation (the length of the portion excluding the opening width of the discharge port 16 from the peripheral length of the valve chamber 17). The section is extremely short.

  Note that what permits or blocks the discharge of the slurry-like active material from the discharge port 16 is merely the coating valve 13, and the opening and closing of the discharge port 16 by the camshaft 20 that also serves as the valve body is, for example, coating In order to prevent the slurry-like active material from leaking from the discharge port 16 due to residual pressure or time lag remaining between the coating valve 13 and the discharge port 16 after the valve 13 is closed.

  Here, in addition to the application shape of the slurry-like active material P to the current collector W, the opening / closing timing of the coating valve 13 and the return valve 14, the opening / closing timing of the discharge port 16 by the camshaft 20 in the coating head 3 is also determined. A time chart is shown in FIG.

  As is apparent from FIG. 7, the application start end portion of the slurry-like active material coincides with the valve opening timing of the coating valve 13 and the valve closing timing of the return valve 14, respectively, and the application end of the slurry-like active material is applied. The portions coincide with the valve closing timing of the coating valve 13 and the valve opening timing of the return valve 14, respectively. Further, at least an instantaneous valve closing timing of the discharge port 16 by the camshaft 20 in the coating head 3 coincides with the valve closing timing of the coating valve 13 and the valve opening timing of the return valve 14 described above. Yes. Then, as described above with reference to FIG. 2, in the process in which the current collector W continuously runs in a state of being wound around the backup roll 6, the current collector W is slurried by the coating head 3. The active material P is applied intermittently at a predetermined interval.

  FIG. 8 shows an example of synchronizing the opening / closing timing of the discharge port 16 by the camshaft 20 in addition to the coating valve 13 and the return valve 14 described above. Here, on the basis of the rotation of the backup roll 6 proportional to the coating speed, the opening / closing timing of the coating valve 13 and the return valve 14 and the opening / closing timing of the discharge port 16 by the camshaft 20 are respectively synchronized. Therefore, in the present embodiment, the coating valve 13 and the return valve 14 are mechanically operated by the cam plate 38 or 39. In addition to the gear train 30 in which the small-diameter, medium-diameter, and large-diameter timing gears 27 to 29 are coaxially provided in addition to the backup roll 6 and the coaxial-integrated timing gear 26, the gear train 30 has a large diameter. An idle gear 31 that meshes with the timing gear 29 is provided. The idle gear 31 is coaxially integrated with the timing gear 32.

  A timing chain 33 is wound between the timing gear 26 on the backup roll 6 side and the medium-diameter timing gear 28 in the gear train 30, and the gear train 30 is accelerated in synchronization with the rotation of the backup roll 6. Synchronously rotate. Further, a timing chain 34 is wound around the timing gear 32 coaxially integrated with the idle gear 31 and the timing gear 24 on the camshaft 20 side shown in FIGS. 6 is rotated in synchronism with the rotation of 6.

  A cam plate 38 for driving the coating valve 13 is coaxially integrated with the small-diameter and large-diameter timing gears 35, 36. Similarly, a cam plate 39 for driving the return valve 14 is coaxially integrated with the timing gear 37. It is supposed to be. A timing chain 40 is wound between the small-diameter timing gear 27 in the gear train 30 and the timing gear 36 on the cam plate 38 side. As a result, the cam plate 38 is accelerated more than the gear train 30 and rotates synchronously. It will be. A timing chain 41 is wound between the timing gear 35 on the cam plate 38 side and the timing gear 37 on the other cam plate 39 side, and both the cam plates 38 and 39 are synchronized at a constant speed. Will rotate.

  The profile shapes of the cam plates 38 and 39 that drive the coating valve 13 and the return valve 14 are in an opposite phase relationship to achieve the opening / closing timing as shown in FIG. By rotating, each of the coating valve 13 and the return valve 14 is driven to open and close four times per rotation of the cam plates 38 and 39. As described above with reference to the time chart of FIG. 7, the coating valve 13 and the return valve 14 are reversely operated in synchronization with each other. If the coating valve 13 is in the open state, the return is performed. The profile of the valve 14 is set so that the valve 14 is closed and, conversely, the return valve 14 is opened when the coating valve 13 is closed.

  Here, although not shown in FIG. 8, the timing gear 28 that rotates synchronously with the backup roll 6 and the other timing gears 27 and 29, particularly the camshaft 20 on the coating head 3 side, are driven via the timing chain 33. In addition to providing a clutch for connecting / disconnecting rotation transmission to / from the timing gear 29 at an arbitrary timing, rotation of a servo motor or the like for independently driving the timing gears 27 and 29 to rotate. Driving means are provided.

  Further, as shown in FIG. 8, each timing gear and the timing chain wound around them are provided with alignment marks 42 to manage the presence or absence of timing deviation.

  Therefore, according to the system configured in this way, as shown in FIG. 2, in the process in which the current collector W runs around the backup roll 6, the coating is performed in synchronization with the rotation of the backup roll 6. Since the valve 13 and the return valve 14 are opened and closed, the active material P is discharged from the discharge port 16 of the coating head 3, and the active material P is intermittently applied onto the current collector W.

  More specifically, as shown in FIG. 7, since the opening timing of the coating valve 13 and the closing timing of the return valve 14 are almost the same, the coating film thickness is increased at the starting end portion of the active material P to be applied. It is applied so as to change gradually and eventually become a constant thickness. Similarly, since the closing timing of the coating valve 13 and the opening timing of the return valve 14 are almost the same, the coating film thickness gradually changes so that the coating film thickness is reduced at the terminal portion of the applied active material P. Application of the active material is interrupted. Thus, the coating film thickness gradually changes at the start and end portions of the coating film of the active material P applied on the current collector W, which is preferable in terms of shape.

  Then, in synchronization with the closing timing of the coating valve 13, the camshaft 20 accommodated in the coating head 3 is rotated once as shown in FIG. The synchronous rotation of the camshaft 20 is performed by, for example, the clutch connection / disconnection described above. That is, in synchronization with the closing timing of the coating valve 13, the camshaft 20 is rotated once in the direction of the arrow in FIG. 5 with the phase position S1 in FIG. 5 as the start and end portions of rotation. As long as the camshaft 20 is in the phase position S1, the discharge port 16 remains open.

  As a result, the nose portion 22a of the cam lobe 22 in the camshaft 20 passes through the discharge port 16 in the middle of its rotation as shown by the solid line in the figure, so that the camshaft 20 has its discharge port only for a very short time or momentarily. 16 (the opening of the discharge port 16 facing the valve chamber 17) is closed. As a result, it is possible to prevent the active material P from leaking from the discharge port 16 due to residual pressure or time lag remaining between the coating valve 13 and the discharge port 16 after the closing operation of the coating valve 13. Thus, the coating quality of the active material P is stable and good.

  In addition, since the opening / closing timing of the coating valve 13 and the return valve 14 and the opening / closing timing of the discharge port 16 by the camshaft 20 are mechanically synchronized with the rotation of the backup roll 6, there is no occurrence of a synchronization shift or the like. In addition to improving the coating quality, it is possible to follow the increase in the coating speed of the active material P, thereby improving the productivity.

  FIG. 9 is a diagram showing a second embodiment of the present invention, and shows a modification of FIG.

  In FIG. 9, the discharge port 16 and the communication passage 18 are formed not at the diameter of the valve chamber 17 but at a position close to the tangential direction of the valve chamber 17, as is apparent from comparison with FIG. 5. The shaft portion 21 is concentric with the valve chamber 17 so that the nose portion 22a of the cam lobe 22 is inscribed in the valve chamber 17 at any position. As in the first embodiment, when the camshaft 43 is rotated once in synchronism with the closing timing of the coating valve 13, the phase position S2 is used as the rotation start and end portions in FIG. One rotation is made in the direction of the arrow.

  In the second embodiment, in addition to the effects similar to those of the first embodiment, a suck back effect is obtained when the camshaft 43 makes one rotation, that is, the nose portion 22a of the cam lobe 22 is opened to the discharge port 16. When passing through the section, the effect of drawing the active material P remaining on the discharge port 16 side into the valve chamber 17 side can be expected, and excessive leakage of the active material P from the discharge port 16 can be further prevented. It becomes.

  FIG. 10 is a diagram showing a third embodiment of the present invention, and similarly shows a modification of FIG.

  In the form of FIG. 10, as is clear from comparison with FIG. 5, the discharge port 16 and the communication path 18 are formed on the same plane, but are separated from the valve chamber 17, and the valve body extends over both. 45 is arranged so that it can appear and disappear. A camshaft 44 is arranged eccentrically in the valve chamber 17, and the rotation of the camshaft 44 is converted into a linear motion of the valve body 45 so that the valve body 45 is projected and retracted. Further, the camshaft 44 has the phase position S3 as the start and end portions of one rotation, and closes the discharge port 16 at the timing when the valve body 45 is pushed up by the nose portion 22a of the cam lobe 22 as shown by the solid line. It has become. The valve body 45 is sealed with a seal member 46.

  In the third embodiment, the same effect as in the first embodiment can be obtained.

DESCRIPTION OF SYMBOLS 3 ... Coating head 3a ... Head main body 4 ... Coating apparatus 6 ... Backup roll 10 ... Slurry tank (slurry substance supply source)
12 ... Supply path 13 ... Coating valve (open / close valve)
16 ... Discharge port 17 ... Valve chamber 20 ... Cam shaft (cam member)
22 ... Cam lobe (valve)
43 ... Camshaft (cam member)
44. Camshaft (cam member)
45 ... Valve body P ... Slurry active material (slurry material)
W ... Current collector (base material)

Claims (6)

A coating head is provided that is disposed close to the substrate to which the slurry-like substance is to be applied, and the slurry-like substance is pumped from the slurry-like substance supply source, and the coating head is moved by relative movement between the substrate and the coating head. A coating device that discharges slurry-like material from the substrate and applies it intermittently on the substrate,
The coating head is
A slit-like discharge port formed in the head body;
A cam member rotatably accommodated in the back side of the discharge port in the head body;
With
A coating apparatus characterized in that the discharge port is closed directly or indirectly at a rate of once per rotation of the cam member.   2. The discharge port is closed directly or indirectly at a rate of once per rotation of the cam member for a closed section shorter than an open section during the one rotation. The coating apparatus as described.   The coating apparatus according to claim 2, wherein the cam member also serves as a valve body, and the discharge port is directly opened and closed by a profile shape of the cam member also serving as the valve body. .   3. The coating according to claim 2, further comprising: a valve body that is driven to open and close by the cam member in proximity to the cam member, and the valve body opens and closes the discharge port. apparatus. A main opening / closing valve is interposed in a supply path connecting the slurry-like substance supply source and the coating head,
The coating apparatus according to claim 3 or 4, wherein the opening / closing timing of the opening / closing valve and the opening / closing timing of the valve body are mechanically synchronized. While the base material is designed to run in a state of being wound around a backup roll,
The coating head is placed close to the winding part by this backup roll,
6. The coating apparatus according to claim 5, wherein the opening and closing timing of the valve body is mechanically synchronized with the rotation of the backup roll.