Coating dies and coating equipment

Abstract

This coating die 2 comprises a manifold 22, a discharge port 26, and a rotating body 42 that is accommodated in the manifold 22 and that is capable of forming a first slit 52 by using the outer surface of the rotating body 42 and the inner surface of the manifold 22. The manifold 22, the discharge port 26, and the rotating body 42 are long in a first direction Y intersecting the discharge direction X of a coating. The rotating body 42 is capable of rotating about rotating shaft extending in the first direction Y, the rotating body 42 having a long circumferential portion 50a of a prescribed first length at a prescribed position on an outer surface 50 and having a short circumferential portion 50b of a second length less than the first length at a position separated from the long circumferential portion 50a in the first direction Y, and moreover forming, by using the long circumferential portion 50a, a first slit 52 that is longer than a first slit 52 formed by using the short circumferential portion 50b.

Description

Technical Field

[0001] The present invention relates to a coating die and a coating apparatus.

Background Art

[0002] In recent years, with the spread of electric vehicles (EVs), hybrid vehicles (HVs), plug-in hybrid vehicles (PHVs), etc., the shipments of secondary batteries have been increasing. In particular, the shipments of lithium-ion secondary batteries have been increasing. A general secondary battery mainly includes a positive electrode plate, a negative electrode plate, a separator, and an electrolyte. Electrode plates such as positive electrode plates and negative electrode plates have a structure in which an electrode active material is laminated on the surface of a current collector made of a metal foil. Conventionally, as a method for manufacturing such an electrode plate, an intermittent coating apparatus including a die for discharging an electrode slurry and an intermittent valve for switching the supply and non-supply of the electrode slurry to the die is used to intermittently apply the electrode slurry to the surface of a long current collector (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The discharge amount of the electrode slurry from the coating die may be non-uniform in the coating width direction. When the discharge amount of the electrode slurry becomes non-uniform, the thickness of the electrode active material layer becomes non-uniform, and the performance of the secondary battery may be impaired. For this reason, a plurality of choke bars arranged in the coating width direction are provided in the conventional coating die. Each choke bar can move forward and backward in the flow path of the electrode slurry, and the discharge amount of the electrode slurry in the coating width direction can be adjusted by adjusting the protruding amount of each choke bar.

[0005] However, even when the discharge rate was adjusted to be uniform during the preparation stage for the coating process, the dimensions of the coating die and the viscosity of the electrode slurry would change with temperature, sometimes resulting in an uneven discharge rate during the coating process. Conventionally, the choke bar was operated each time the discharge rate became uneven in order to equalize it.

[0006] This disclosure is made in view of these circumstances, and one of its purposes is to provide a technology that improves workability in coating processes. [Means for solving the problem]

[0007] One aspect of the present disclosure is a coating die for applying paint to a workpiece. The coating die comprises a manifold for temporarily storing paint, a discharge port for discharging the paint from the manifold toward the workpiece, and a rotating body rotatably housed in the manifold and having an outer surface facing the inner surface of the manifold, and capable of forming a first slit through which the paint toward the discharge port passes by the gap between the inner and outer surfaces. The manifold, discharge port, and rotating body are elongated in a first direction intersecting the direction of paint discharge from the discharge port. The rotating body is rotatable about a pivot axis extending in the first direction, and has a long circumferential portion at a predetermined position on its outer surface having a predetermined first length in the circumferential direction of the pivot axis, and a short circumferential portion at a position offset from the long circumferential portion in the first direction on its outer surface having a second length shorter than the first length in the circumferential direction of the pivot axis, and the long circumferential portion forms a first slit longer than the first slit formed by the short circumferential portion.

[0008] Another aspect of the present disclosure is a coating apparatus. This coating apparatus comprises a coating die of the above-described aspect for applying paint to a workpiece, and a supply device for supplying paint to the coating die.

[0009] Any combination of the above components, as well as conversions of the expression of the present invention between methods, apparatus, systems, etc., are also valid embodiments of the present invention. [Effects of the Invention]

[0010] According to this disclosure, it is possible to improve workability in coating processes. [Brief explanation of the drawing]

[0011] [Figure 1] This is a schematic diagram of a coating apparatus according to an embodiment. [Figure 2] This is a perspective view of a coating die. [Figure 3] This is an exploded view of a coating die. [Figure 4] Figure 4(A) is a perspective view of the rotating body. Figure 4(B) is a front view of the rotating body. Figure 4(C) is a top view of the rotating body. [Figure 5] Figures 5(A) and 5(B) are perspective views of a coating die cut at the center in the first direction. [Figure 6] Figure 6(A) is a perspective view of the coating die cut at the center in the first direction. Figure 6(B) is a perspective view of the coating die cut between the center and the end in the first direction. Figure 6(C) is a perspective view of the coating die cut at the end in the first direction. [Figure 7] Figure 7(A) is a perspective view of the first block and shim. Figure 7(B) is a plan view of the first block and shim. [Modes for carrying out the invention]

[0012] The present disclosure will be described below with reference to the drawings, based on preferred embodiments. The embodiments are illustrative and not limiting, and not all features or combinations thereof described in the embodiments are necessarily essential to the present disclosure. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and redundant descriptions are omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and are not to be interpreted restrictively unless otherwise specified. Furthermore, where terms such as "first," "second," etc. are used in this specification or claims, unless otherwise specified, these terms do not indicate any order or importance, but are used to distinguish one configuration from another. In addition, some components that are not important for explaining the embodiments are omitted in each drawing.

[0013] Figure 1 is a schematic diagram of a coating apparatus 1 according to an embodiment. The coating apparatus 1 comprises a coating die 2 and a supply device 3. The coating die 2 applies paint 18 to the object to be coated 16. The coating apparatus 1 according to this embodiment is used to manufacture electrode plates for secondary batteries. Electrode plates for secondary batteries are sheet-shaped electrode materials obtained by applying electrode slurry to a current collector and drying it. Therefore, in this embodiment, the object to be coated 16 is the current collector of a secondary battery, and the paint 18 is the electrode slurry of a secondary battery. The current collector is, for example, a metal foil. The electrode slurry is, for example, a mixture of a positive electrode active material or a negative electrode active material and a solvent.

[0014] In a typical lithium-ion secondary battery, the positive electrode plate is manufactured by coating an aluminum foil with a slurry containing a positive electrode active material such as lithium cobalt oxide or lithium iron phosphate. The negative electrode plate is manufactured by coating a copper foil with a slurry containing a negative electrode active material such as graphite. The coating apparatus 1 can also be used to manufacture items other than electrode plates.

[0015] The coating die 2 is positioned so that its discharge port 26 faces the circumferential surface of the backup roll 20 at a predetermined distance. The object to be coated 16 is continuously conveyed by the rotation of the backup roll 20 to a position where the backup roll 20 and the discharge port 26 face each other.

[0016] The supply device 3 supplies paint 18 to the coating die 2. The supply device 3 in this embodiment includes an intermittent valve 4, a tank 6, a pump 8, a supply line 10, a return line 12, and a die supply line 14. The intermittent valve 4 is connected to the coating die 2 via the die supply line 14. The tank 6 is connected to the intermittent valve 4 via the supply line 10 and the return line 12. The tank 6 stores the paint 18. A pump 8 is provided in the supply line 10, and the pump 8 drives the paint 18 from the tank 6 to the intermittent valve 4. The intermittent valve 4 supplies the paint 18 supplied from the tank 6 to the coating die 2 via the die supply line 14. Alternatively, the intermittent valve 4 returns the paint 18 supplied from the tank 6 to the tank 6 via the return line 12.

[0017] The intermittent valve 4 supplies paint 18 to the coating die 2, allowing the paint 18 to be discharged from the coating die 2 and form a coated area 18a of paint 18 on the workpiece 16. The intermittent valve 4 also returns the paint 18 to the tank 6, stopping the discharge of paint 18 from the coating die 2 and forming an uncoated area 16a of paint 18 on the workpiece 16. In other words, the intermittent valve 4 allows for intermittent coating of paint 18 to the workpiece 16. The uncoated area 16a is used for purposes such as attaching the center lead of an electrode. Note that the coating performed by the coating apparatus 1 is not limited to intermittent coating.

[0018] FIG. 2 is a perspective view of the coating die 2. FIG. 3 is an exploded view of the coating die 2. The coating die 2 includes a manifold 22, a supply port 24, and a discharge port 26. The manifold 22 temporarily stores the paint 18. The supply port 24 communicates the manifold 22 with the outside of the coating die 2. The paint 18 is supplied from the outside of the coating die 2, that is, from the supply device 3, to the manifold 22 through the supply port 24. The discharge port 26 discharges the paint 18 in the manifold 22 toward the workpiece 16 to be coated. Hereinafter, the direction in which the paint 18 is discharged from the discharge port 26 is defined as the discharge direction X.

[0019] The coating die 2 of the present embodiment has a structure in which a first block 28, a shim 30 (dicker), and a second block 32 are laminated in this order. The first block 28, the shim 30, and the second block 32 are long in a first direction Y intersecting the discharge direction X and are laminated in a second direction Z intersecting the discharge direction X and the first direction Y. In the present embodiment, the discharge direction X, the first direction Y, and the second direction Z intersect perpendicularly to each other. Further, both the discharge direction X and the first direction Y are directions extending horizontally, and the second direction Z is a direction extending vertically.

[0020] The first block 28 includes a central block 28a that is long in the first direction Y and a pair of end blocks 28b that sandwich the central block 28a in the first direction Y. Each end block 28b is connected to the central block 28a by a fastening member (not shown). The first block 28 has a flat substantially rectangular parallelepiped shape and is arranged such that one main surface faces the second block 32 side. The first block 28 has a first recess 34 on the main surface facing the second block 32 side. The first recess 34 has a semi-cylindrical shape that is long in the first direction Y. Further, the first block 28 has a first protrusion 36 that protrudes in the discharge direction X. The first protrusion 36 is long in the first direction Y and is arranged flush with the main surface facing the second block 32 side. A supply port 24 is provided in the central block 28a. One end of the supply port 24 is connected to the first recess 34. The other end of the supply port 24 is connected to the die supply pipeline 14. In the present embodiment, the supply port 24 is arranged at the center of the first block 28 in the first direction Y.

[0021] The second block 32 includes a central block 32a that is elongated in the first direction Y, and a pair of end blocks 32b that sandwich the central block 32a in the first direction Y. Each end block 32b is connected to the central block 32a by fastening members (not shown). The second block 32 is a flat, substantially rectangular parallelepiped, and is positioned so that one main surface faces the first block 28. The second block 32 has a second recess 38 on the main surface facing the first block 28. The second recess 38 is a semi-cylindrical shape that is elongated in the first direction Y. The diameter of the semi-cylindrical part of the second recess 38 is smaller than the diameter of the semi-cylindrical part of the first recess 34. The second recess 38 faces the first recess 34 in the second direction Z. The second block 32 also has a second projection 40 that protrudes in the discharge direction X. The second projection 40 is elongated in the first direction Y and is positioned flush with the surface facing the first block 28. The second projection 40 faces the first projection 36 in the second direction Z.

[0022] The shim 30 is a roughly U-shaped plate material that surrounds three sides of the first recess 34, excluding the side with the first protrusion 36, and three sides of the second recess 38, excluding the side with the second protrusion 40, when viewed from the second direction Z. The first block 28 and the second block 32 are connected to each other by fastening members (not shown) with the shim 30 sandwiched in the second direction Z. The fastening members connecting the first block 28 and the second block 32 are inserted into each block in the region that overlaps with the shim 30 when viewed from the second direction Z. Therefore, the first block 28 and the second block 32 are connected to each other in the regions around the first recess 34 and the second recess 38, excluding the sides with the respective protrusions.

[0023] The interposition of a shim 30 between the first block 28 and the second block 32 creates a gap between the first protrusion 36 and the second protrusion 40 equal to the thickness of the shim 30. This gap constitutes the discharge port 26. The discharge port 26 is elongated in the first direction Y. Furthermore, with the first block 28 and the second block 32 connected to each other, a roughly cylindrical space is formed by the first recess 34 and the second recess 38. This space constitutes the manifold 22. The manifold 22 is elongated in the first direction Y.

[0024] The coating die 2 has a first region R1 and a second region R2 that are offset from each other in the first direction Y. When the first slit 52, which will be described later, is not formed, the first region R1 discharges paint 18 at a predetermined first discharge rate. On the other hand, the second region R2 discharges paint 18 at a second discharge rate that is less than the first discharge rate. In other words, the coating die 2 has variation in the discharge rate of paint 18 (amount discharged per unit time) in the first direction Y. One of the factors that causes variation in discharge rate is the connection position of the supply port 24 to the manifold 22. Generally, in the coating die 2, the discharge rate is high in the region including the supply port 24, and tends to decrease as you move away from that region.

[0025] In this embodiment, the supply port 24 is connected to the central part of the manifold 22 in the first direction Y. Therefore, the coating die 2 has a first region R1 with a large discharge volume in the central part of the first direction Y, and a second region R2 with a small discharge volume at both ends of the first direction Y. In addition, the first block 28 and the second block 32 are fastened together at both ends in the first direction Y. Therefore, the discharge port 26 is more likely to open in the center than at both ends. From this point of view as well, the central part of the first direction Y tends to become the first region R1, and the ends of the first direction Y tend to become the second region R2.

[0026] Furthermore, the amount of paint 18 discharged gradually decreases from the center of the first direction Y towards both ends. Therefore, any first position in the first direction Y becomes the first region R1, and a second position located closer to the ends than the first position becomes the second region R2. In other words, the first region R1 is not limited to the center of the first direction Y, and the second region R2 is not limited to both ends of the first direction Y. However, for convenience, the figures show the center as the first region R1 and both ends as the second region R2.

[0027] Furthermore, as each block and shim 30 expands and contracts with temperature changes, the dimensions (opening) of the discharge port 26 may change. Also, the viscosity of the paint 18 may change with temperature changes in the paint 18. When the dimensions of the discharge port 26, the viscosity of the paint 18, etc., change, the difference between the amount of paint 18 discharged in the first region R1 and the amount of paint 18 discharged in the second region R2 may also change. In other words, the tendency of variation in the discharge amount in the first direction Y may change during the coating process.

[0028] To suppress such variations in discharge volume, the coating die 2 is equipped with a rotating body 42. Figure 4(A) is a perspective view of the rotating body 42. Figure 4(B) is a front view of the rotating body 42. Figure 4(C) is a plan view of the rotating body 42. Figures 4(A) to 4(C) show the rotating body 42 in the reference position described later. The rotating body 42 is based on a cylinder that is long in the first direction Y, and has a shape in which a part of the circumferential surface of the cylinder is cut out over approximately the entire length of the first direction Y. The diameter of the cylinder is substantially equal to the diameter of the semi-cylinder of the second recess 38. The rotating body 42 has disc-shaped support parts 44 at both ends in the first direction Y. The rotating body 42 also has a main body part 46 that remains uncut between the pair of support parts 44.

[0029] The rotating body 42 is rotatably housed in the manifold 22. The rotating body 42 is rotatable about a pivot axis Ax extending in a first direction Y. The pivot axis Ax corresponds to the central axis of the cylinder which is the basic shape of the rotating body 42. A rotating operating body 48 is connected to each support portion 44, which protrudes outward from the coating die 2 in the first direction Y (see Figures 2 and 3). Each rotating operating body 48 can rotate about the pivot axis Ax. As the rotating operating body 48 rotates, the rotating body 42 rotates about the pivot axis Ax.

[0030] The main body 46 has an outer surface 50. The outer surface 50 faces the inner surface of the manifold 22. The outer surface 50 corresponds to the portion of the cylindrical circumferential surface that remains uncut. The main body 46 is thickest in the center in the first direction Y and gradually becomes thinner towards both ends in the first direction Y. Therefore, the length of the outer surface 50 in the circumferential direction of the pivot axis Ax differs depending on the position in the first direction Y. In other words, the outer surface 50 has a long circumferential portion 50a with a predetermined first length in the circumferential direction of the pivot axis Ax at a predetermined position in the first direction Y, and a short circumferential portion 50b with a second length shorter than the first length in the circumferential direction of the pivot axis Ax at a position offset from the long circumferential portion 50a in the first direction Y. The first and second lengths can be appropriately set based on experiments and simulations.

[0031] The rotating body 42 of this embodiment has a long circumference portion 50a in the portion included in the first region R1 on the outer surface 50, and a short circumference portion 50b in the portion included in the second region R2 on the outer surface 50. In the rotating body 42 of this embodiment, the position of the long circumference portion 50a in the first direction Y coincides with the position of the supply port 24 in the first direction Y. It is sufficient that at least a portion of the positions of the long circumference portion 50a and the supply port 24 in the first direction Y overlap. Preferably, the centers of the long circumference portion 50a and the supply port 24 in the first direction Y coincide. Furthermore, the long circumference portion 50a is located in the central part of the rotating body 42 in the first direction Y, and the short circumference portion 50b is located at both ends of the rotating body 42 in the first direction Y.

[0032] Furthermore, the position of the long circumference portion 50a is not limited to the center of the first direction Y, and the position of the short circumference portion 50b is not limited to both ends of the first direction Y. In other words, the outer surface 50 may have a long circumference portion 50a at any first position in the first direction Y, and a short circumference portion 50b at a second position closer to the ends than the first position. However, for convenience, in each figure, the center of the outer surface 50 is represented as the long circumference portion 50a, and both ends as the short circumference portion 50b. In this embodiment, the length of the outer surface 50 in the circumferential direction of the pivot axis Ax gradually decreases from the long circumference portion 50a towards the short circumference portion 50b.

[0033] Furthermore, the shape of the rotating body 42 can be appropriately changed depending on the arrangement of the first region R1 and the second region R2. For example, the rotating body 42 may have a shape in which the length in the circumferential direction of the rotation axis Ax is shorter in the center and longer at both ends, or it may have a shape in which one end in the first direction Y is the longest and gradually gets shorter towards the other end. Alternatively, it may have a shape in which multiple long and short undulations are arranged in the first direction Y.

[0034] Figures 5(A) and 5(B) are perspective views of the coating die 2 cut at the center in the first direction Y. As shown in Figure 5(A), the rotating body 42 can be in a state where the main body 46 is housed in the second recess 38. Hereinafter, the rotation angle of the rotating body 42 in this state will be defined as 0°, and the rotation angle of 0° will be defined as the reference position. The rotating body 42 can also be rotated from the reference position to a predetermined angle in a direction where the front end in the discharge direction X enters the first recess 34 side, as shown in Figure 5(B). In this embodiment, the rotating body 42 can be rotated up to 90° from the reference position.

[0035] As described above, the diameter of the semi-cylinder of the first recess 34 is larger than the diameter of the semi-cylinder of the second recess 38. Also, the diameter of the cylinder, which is the basic shape of the rotating body 42, is substantially equal to the diameter of the semi-cylinder of the second recess 38. Therefore, when the rotating body 42 is in the reference position, the outer surface 50 is in contact with the inner surface of the second recess 38. Furthermore, when the rotating body 42 rotates from the reference position and the outer surface 50 and the inner surface of the first recess 34 face each other, a gap is created between the outer surface 50 and the inner surface of the first recess 34. This gap constitutes the first slit 52. The paint 18 in the manifold 22 passes through the first slit 52 and heads toward the discharge port 26. By forming the first slit 52 between the manifold 22 and the discharge port 26, the flow resistance of the paint 18 can be increased, and thus the amount of paint 18 discharged can be reduced.

[0036] Figure 6(A) is a perspective view of the coating die 2 cut at the center in the first direction Y. Figure 6(B) is a perspective view of the coating die 2 cut between the center and the end in the first direction Y. Figure 6(C) is a perspective view of the coating die 2 cut at the end in the first direction Y. Figures 6(A) to 6(C) show a rotating body 42 rotated 45° from the reference position.

[0037] The outer surface 50 of the rotating body 42 has a long circumference portion 50a and a short circumference portion 50b. When the rotating body 42 is rotated from the reference position, the long circumference portion 50a begins to enter the first recess 34 before the short circumference portion 50b. Therefore, as shown in Figures 6(A) and 6(C), the length of the first slit 52 is longer in the long circumference portion 50a and shorter in the short circumference portion 50b. In this embodiment, the length of the outer surface 50 gradually decreases from the center to both ends in the first direction Y. Therefore, as shown in Figures 6(A) to 6(C), the length of the first slit 52 gradually decreases from the center to both ends in the first direction Y.

[0038] The rotating body 42 has a long circumference portion 50a in the first region R1 and a short circumference portion 50b in the second region R2. Therefore, the rotating body 42 can form a first slit 52 that is longer in the first region R1 than in the second region R2. The longer the first slit 52, the greater the flow resistance of the paint 18 before it passes through the first slit 52, and the lower the flow rate. Therefore, by forming the first slit 52 as described above, the amount of paint 18 discharged in the first region R1, where the amount of paint 18 discharged is high when the first slit 52 is not formed, can be greatly reduced. Also, the amount of paint 18 discharged in the second region R2, where the amount of paint 18 discharged is low when the first slit 52 is not formed, can be greatly reduced. As a result, the amount of paint 18 discharged can be made uniform in the first region R1 and the second region R2.

[0039] Furthermore, the length of the first slit 52 in the first region R1 and the second region R2 can be changed simply by changing the rotation angle of the rotating body 42. Also, as shown in Figure 4(C), the ridge (contour) of the outer surface 50 extending in the first direction Y is curved. In other words, the amount of decrease of the outer surface 50 from the center to both ends in the first direction Y is not uniform. For this reason, the length of the first slit 52 can be increased or decreased by different amounts in the first region R1 and the second region R2 by changing the rotation angle of the rotating body 42. Thus, the amount of paint 18 discharged from the first region R1 and the second region R2 can be easily adjusted. As a result, even if the tendency for variation in the discharge amount in the first direction Y changes during the coating process due to changes in the dimensions of the discharge port 26 or the viscosity of the paint 18, the discharge amount can be easily made uniform.

[0040] The rotation angle of the rotating body 42 can be adjusted by operating the rotation operator 48. The rotation operator 48 may be operated manually by an operator or by a drive device such as a motor (not shown). Alternatively, the rotation angle of the rotating body 42 may be feedback controlled by combining a known flow meter installed at the discharge port 26 with a drive device.

[0041] Furthermore, the coating die 2 has a second slit 54 through which the paint 18 traveling from the manifold 22 to the discharge port 26 passes. One end of the second slit 54 is connected to the first slit 52, and the other end is connected to the discharge port 26. The paint 18 supplied from the supply device 3 flows into the manifold 22 from the supply port 24. The paint 18 is temporarily stored in the manifold 22, then passes through the first slit 52 and the second slit 54 in that order to reach the discharge port 26, and is discharged from the discharge port 26. By temporarily storing the paint 18 in the manifold 22 before sending it to the discharge port 26, the discharge stability of the paint 18 can be improved.

[0042] The second slit 54 is formed by the first block 28, the shim 30, and the second block 32. Figure 7(A) is a perspective view of the first block 28 and the shim 30. Figure 7(B) is a plan view of the first block 28 and the shim 30.

[0043] As shown in Figures 7(A) and 7(B), the shim 30 is cut out in a region that overlaps with the manifold 22 when viewed from the second direction Z, and in a region from the manifold 22 to the discharge port 26. Therefore, the shim 30 has a main body portion 56 that extends along the edge of the manifold 22 opposite to the discharge port 26, and a pair of arm portions 58 that protrude toward the discharge port 26 from both ends of the main body portion 56 in the first direction Y. The second slit 54 is formed by the central block 28a of the first block 28 and the central block 32a of the second block 32, which face each other in the second direction Z, and the pair of arm portions 58 that face each other in the first direction Y. The second slit 54 is elongated in the first direction Y.

[0044] The second slit 54 has a small resistance portion 54a that generates a predetermined first flow resistance in the paint 18, and a large resistance portion 54b that generates a second flow resistance in the paint 18 that is greater than the first flow resistance. The magnitudes of the first and second flow resistances can be appropriately set based on experiments and simulations. The first block 28 of this embodiment has a recessed portion 60 that is recessed in the second direction Z in the region between the first recess 34 and the first protrusion 36. The recessed portion 60 extends in the first direction Y along the edge of the first recess 34 on the discharge port 26 side. Also, when viewed from the second direction Z, the recessed portion 60 has a triangular shape with the edge of the first recess 34 as its base and a vertex angle that protrudes toward the discharge port 26 side.

[0045] In the second slit 54, the flow path cross-sectional area increases in the portion where the recessed portion 60 is provided. A larger flow path cross-sectional area reduces the flow resistance of the paint 18. Furthermore, the longer the length of the recessed portion 60 in the flow path of the paint 18 extending from the manifold 22 in the discharge direction X, the lower the flow resistance of the paint 18. Therefore, in the second slit 54, the portion including the apex angle of the recessed portion 60 becomes a low-resistance portion 54a, and the portion including the bottom angle of the recessed portion 60 becomes a high-resistance portion 54b.

[0046] In the second slit 54 of this embodiment, the apex angle of the recessed portion 60 is located in the center of the first direction Y. Also, the bottom angles of the recessed portion 60 are located at both ends of the first direction Y. Therefore, the small resistance portion 54a is provided at a position corresponding to the first region R1, and the large resistance portion 54b is provided at a position corresponding to the second region R2. With the second slit 54, when the first slit 52 is not formed, the amount of paint 18 discharged is greater in the first region R1 and less in the second region R2.

[0047] The rotating body 42 changes the degree to which it reduces the discharge amount of the paint 18 by forming the first slit 52, thereby homogenizing the variation in the discharge amount in the first direction Y. In addition, the second slit 54 can widen the difference between the first discharge amount and the second discharge amount. By widening the difference between the first and second discharge amounts, the range of rotation angles that the rotating body 42 can take to achieve uniform discharge amounts can be expanded. Therefore, the range of adjustment of the discharge amount by the rotating body 42 can be widened. Furthermore, it becomes possible to more reliably create a state in which uniform discharge amounts can be achieved by the rotating body 42.

[0048] A first region R1 may be formed on the coating die 2 by providing a small resistance portion 54a, and a second region R2 may be formed on the coating die 2 by providing a large resistance portion 54b. In other words, the positions of the first region R1 and the second region R2 may be arbitrarily set by the arrangement of the small resistance portion 54a and the large resistance portion 54b. This allows the positions of the first region R1 and the second region R2 to be arbitrarily set in accordance with the arrangement of the long circumference portion 50a and the short circumference portion 50b.

[0049] Furthermore, the position of the small resistance portion 54a is not limited to the center of the first direction Y, and the position of the large resistance portion 54b is not limited to both ends of the first direction Y. In other words, the second slit 54 may have a small resistance portion 54a at any first position in the first direction Y, and a large resistance portion 54b at a second position closer to the ends than the first position. However, for convenience, in each figure, the center of the second slit 54 is shown as the small resistance portion 54a, and both ends as the large resistance portion 54b. In this embodiment, the length of the recessed portion 60 in the flow path of the paint 18 gradually decreases from the center of the first direction Y toward both ends. Also, the recessed portion 60 may be provided in the second block 32, or it may be provided in both the first block 28 and the second block 32.

[0050] As described above, the coating die 2 of this embodiment comprises a manifold 22 for temporarily storing paint 18, a discharge port 26 for discharging the paint 18 from the manifold 22 toward the object to be coated 16, and a rotating body 42 that is rotatably housed in the manifold 22 and has an outer surface 50 facing the inner surface of the manifold 22, and the gap between the inner surface and the outer surface 50 forms a first slit 52 through which the paint 18 toward the discharge port 26 passes. The manifold 22, the discharge port 26, and the rotating body 42 are elongated in a first direction Y that intersects with the discharge direction X of the paint 18 from the discharge port 26.

[0051] The rotating body 42 is rotatable about a pivot axis Ax extending in a first direction Y, and has a long circumferential portion 50a having a predetermined first length in the circumferential direction of the pivot axis Ax at a predetermined position on the outer surface 50, and a short circumferential portion 50b having a second length shorter than the first length in the circumferential direction of the pivot axis Ax at a position offset from the long circumferential portion 50a in the first direction Y on the outer surface 50. The rotating body 42 has a first slit 52 formed by the long circumferential portion 50a that is longer than the first slit 52 formed by the short circumferential portion 50b.

[0052] In this way, by forming first slits 52 of different lengths at offset positions in the first direction Y using the rotating body 42, coating variations of the coating die 2 can be canceled out. This makes it possible to uniformize the discharge amount of paint 18 in the discharge width direction. Therefore, the film thickness of the coated section 18a can be uniform in the width direction, improving the performance of the secondary battery. Furthermore, by simply changing the rotation angle of the rotating body 42, the length of the first slits 52 in each region aligned in the first direction Y can be changed. Therefore, the discharge amount of paint 18 from each region can be easily adjusted. This improves workability in the coating process.

[0053] Furthermore, the coating die 2 of this embodiment has a first region R1 in which paint 18 is discharged at a predetermined first discharge amount when the first slit 52 is not formed, and a second region R2 which is offset from the first region R1 in the first direction Y and discharges paint 18 at a second discharge amount less than the first discharge amount. The rotating body 42 has a long circumference portion 50a in the part of the outer surface 50 that is included in the first region R1, and a short circumference portion 50b in the part of the outer surface 50 that is included in the second region R2. This makes it possible to cancel out the difference in the discharge amount of paint 18 between the first region R1 and the second region R2.

[0054] Furthermore, the coating die 2 is equipped with a supply port 24 for supplying paint 18 to the manifold 22 from the outside. The position of the long circumference portion 50a in the first direction Y coincides with the position of the supply port 24 in the first direction Y. Generally, the coating die 2 tends to discharge more paint 18 from the region where the position of the first direction Y coincides with the supply port 24. Therefore, by aligning the position of the long circumference portion 50a in the first direction Y with the supply port 24, it is possible to more effectively equalize coating variations.

[0055] Furthermore, the long circumference portion 50a of this embodiment is positioned in the center of the rotating body 42 in the first direction Y. Generally, the first block 28 and the second block 32 are fastened together at both ends in the first direction Y. Therefore, the coating die 2 tends to discharge more paint 18 from the center in the first direction Y. For this reason, positioning the long circumference portion 50a in the center of the first direction Y makes it possible to more effectively equalize coating variations.

[0056] Furthermore, the coating die 2 of this embodiment has a second slit 54 through which the paint 18 traveling from the manifold 22 toward the discharge port 26 passes. The second slit 54 has a small resistance section 54a that corresponds to the first region R1 and generates a predetermined first flow resistance in the paint 18, and a large resistance section 54b that corresponds to the second region R2 and generates a second flow resistance in the paint 18 that is greater than the first flow resistance. This makes it possible to create a state in which the rotating body 42 can function more effectively or more reliably.

[0057] The embodiments of this disclosure have been described in detail above. The embodiments described above are merely examples of how to implement this disclosure. The content of the embodiments does not limit the technical scope of this disclosure, and many design changes, such as changes, additions, and deletions of components, are possible as long as they do not deviate from the idea of ​​this disclosure as defined in the claims. A new embodiment with design changes will have the effects of both the combined embodiment and the variation. In the embodiments described above, the content in which such design changes are possible is emphasized with notations such as "in this embodiment" or "in this embodiment," but design changes are also permitted even if there are no such notations. Any combination of the above components is also valid as an embodiment of this disclosure. The hatching applied to the cross-section in the drawings does not limit the material of the object to which the hatching is applied.

[0058] The embodiments may be specified by the items described below. [Item 1] A coating die (2) for applying paint (18) to a workpiece (16), A manifold (22) for temporarily storing paint (18), A discharge port (26) that discharges the paint (18) inside the manifold (22) toward the object to be coated (16), The manifold (22) is rotatably housed in the manifold (22), and has an outer surface (50) facing the inner surface of the manifold (22), and a rotating body (42) is capable of forming a first slit (52) through which paint (18) toward the discharge port (26) passes, through the gap between the inner surface and the outer surface (50), The manifold (22), discharge port (26), and rotating body (42) are elongated in a first direction (Y) that intersects with the discharge direction (X) of the paint (18) from the discharge port (26). The rotating body (42) is rotatable about a pivot axis (Ax) extending in a first direction (Y), and has a long circumferential portion (50a) at a predetermined position on its outer surface (50) having a predetermined first length in the circumferential direction of the pivot axis (Ax), and a short circumferential portion (50b) at a position offset from the long circumferential portion (50a) in the first direction (Y) on the outer surface (50) having a second length shorter than the first length in the circumferential direction of the pivot axis (Ax), and a first slit (52) longer than the first slit (52) formed by the short circumferential portion (50b) is formed by the long circumferential portion (50a). Die for coating (2). [Item 2] The coating die (2) has a first region (R1) from which paint (18) is discharged at a predetermined first discharge rate when the first slit (52) is not formed, and a second region (R2) from which paint (18) is discharged at a second discharge rate that is less than the first discharge rate, which is offset from the first region (R1) in the first direction (Y). The rotating body (42) has a long circumference portion (50a) in the part of the outer surface (50) that is included in the first region (R1), and a short circumference portion (50b) in the part of the outer surface (50) that is included in the second region (R2). The coating die (2) described in item 1. [Item 3] It is equipped with a supply port (24) for supplying paint (18) to the manifold (22) from the outside, The position of the long circumference (50a) in the first direction (Y) coincides with the position of the supply port (24) in the first direction (Y). A coating die (2) as described in item 1 or 2. [Item 4] The long circumference portion (50a) is positioned in the central part of the rotating body (42) in the first direction (Y). A coating die (2) as described in any of items 1 to 3. [Item 5] The coating die (2) has a first region (R1) from which paint (18) is discharged at a predetermined first discharge rate when the first slit (52) is not formed, and a second region (R2) from which paint (18) is discharged at a second discharge rate that is less than the first discharge rate, which is offset from the first region (R1) in the first direction (Y). Furthermore, the coating die (2) has a second slit (54) through which the paint (18) traveling from the manifold (22) to the discharge port (26) passes. The second slit (54) has a small resistance portion (54a) that corresponds to the first region (R1) and generates a predetermined first flow resistance in the paint (18), and a large resistance portion (54b) that corresponds to the second region (R2) and generates a second flow resistance in the paint (18) that is greater than the first flow resistance. A coating die (2) as described in any of items 1 to 4. [Item 6] The object to be coated (16) is a current collector of a secondary battery, The paint (18) is an electrode slurry for a secondary battery. A coating die (2) as described in any of items 1 to 5. [Item 7] A coating die (2) described in any of items 1 to 6 for applying paint (18) to the object to be coated (16), The device comprises a supply device (3) that supplies paint (18) to a coating die (2), Coating apparatus (1). [Industrial applicability]

[0059] This invention can be used in coating dies and coating apparatus. [Explanation of Symbols]

[0060] 1 Coating device, 2 Coating die, 3 Supply device, 16 Workpiece, 18 Paint, 22 Manifold, 24 Supply port, 26 Discharge port, 42 Rotating body, 50 Outer surface, 50a Long circumference, 50b Short circumference, 52 First slit, 54 Second slit, 54a Small resistance section, 54b Large resistance section, Ax Rotating axis, R1 First region, R2 Second region, X Discharge direction, Y First direction.

Claims

1. A coating die for applying paint to a workpiece, A manifold for temporarily storing the aforementioned paint, A discharge port for discharging the paint from the manifold toward the object to be coated, The manifold comprises a rotating body that is rotatably housed in the manifold and has an outer surface facing the inner surface of the manifold, and the gap between the inner surface and the outer surface forms a first slit through which the paint toward the discharge port passes, The manifold, the discharge port, and the rotating body are elongated in a first direction intersecting the direction of paint discharge from the discharge port. The rotating body is rotatable around a pivot axis extending in the first direction, and has a long circumferential portion having a predetermined first length in the circumferential direction of the pivot axis at a predetermined position on the outer surface, and has a short circumferential portion having a second length shorter than the first length in the circumferential direction of the pivot axis at a position offset from the long circumferential portion in the first direction on the outer surface, and the long circumferential portion forms a first slit that is longer than the first slit formed by the short circumferential portion. The coating die has a first region for discharging the paint at a predetermined first discharge amount when the first slit is not formed, and a second region that is offset from the first region in the first direction and for discharging the paint at a second discharge amount less than the first discharge amount. The rotating body has the long circumference portion in the part of the outer surface included in the first region, and the short circumference portion in the part of the outer surface included in the second region. The first slit formed in the first region is made longer than the first slit formed in the second region, thereby reducing the difference between the first discharge volume and the second discharge volume. Dies for coating.

2. The manifold is equipped with a supply port for supplying the paint from the outside, The position of the long circumference in the first direction coincides with the position of the supply port in the first direction. A coating die according to claim 1.

3. The aforementioned long circumference portion is positioned in the central part of the rotating body in the first direction. A coating die according to claim 1 or 2.

4. The coating die has a first region for discharging the paint at a predetermined first discharge amount when the first slit is not formed, and a second region that is offset from the first region in the first direction and for discharging the paint at a second discharge amount less than the first discharge amount. Furthermore, the coating die has a second slit through which the paint passing from the manifold toward the discharge port, The second slit has a small resistance portion corresponding to the first region and generating a predetermined first flow resistance in the paint, and a large resistance portion corresponding to the second region and generating a second flow resistance in the paint that is greater than the first flow resistance. A coating die according to any one of claims 1 to 3.

5. The object to be coated is a current collector for a secondary battery, The aforementioned paint is an electrode slurry for a secondary battery. A coating die according to any one of claims 1 to 4.

6. A coating die according to any one of claims 1 to 5 for applying paint to a body to be coated, The system includes a supply device for supplying the paint to the coating die, Coating equipment.

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