CN213194316U

CN213194316U - Coating device

Info

Publication number: CN213194316U
Application number: CN202021601816.7U
Authority: CN
Inventors: 颜海鹏; 曾彪; 王冠超
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd; Shanwei BYD Automobile Co Ltd
Priority date: 2020-08-04
Filing date: 2020-08-04
Publication date: 2021-05-14
Anticipated expiration: 2030-08-04

Abstract

The utility model provides a coating device for treat the coating of scribbling the coating, include: the coating roll and the metering roll are tangent to each other, a first gap is arranged between the coating roll and the metering roll, the coating roll and the metering roll rotate in opposite directions, so that external slurry passes through the first gap to form a coating liquid film coated on the coating roll, and the linear velocity direction of the coating roll is opposite to the moving direction of the piece to be coated at the tangent position of the coating roll and the piece to be coated, so that the coating liquid film is coated on the piece to be coated. The utility model provides a scraper can produce the damage to the flexible particle in the coating liquid film, and then influences coating liquid film quality and causes the technical problem of potential safety hazard.

Description

Coating device

Technical Field

The utility model relates to a coating technology field, in particular to coating device.

Background

The existing coating device scrapes off the coating liquid film on the coating roller through a scraper so as to obtain the coating liquid film with the required thickness, and the scraper can damage flexible particles in the coating liquid film, which can affect the quality of the coating liquid film.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a coating device to solve the scraper and can produce the damage to the flexible particle in the coating liquid film, and then influence the technical problem of coating liquid film quality.

The utility model provides a coating device for treat the coating of scribbling the coating, include: the coating roll and the metering roll are tangent to each other, a first gap is arranged between the coating roll and the metering roll, the coating roll and the metering roll rotate in opposite directions, so that external slurry passes through the first gap to form a coating liquid film coated on the coating roll, and the linear velocity direction of the coating roll is opposite to the moving direction of the piece to be coated at the tangent position of the coating roll and the piece to be coated, so that the coating liquid film on the coating roll is coated on the piece to be coated.

The coating roll is provided with a first rotating shaft, the coating roll can rotate around the first rotating shaft, the metering roll is provided with a second rotating shaft, the metering roll can rotate around the second rotating shaft, and the distance between the first rotating shaft and the second rotating shaft is adjustable, so that the size of a first gap between the coating roll and the metering roll can be adjusted.

Wherein, coating unit still includes first deflector roll and second deflector roll, first deflector roll with the second deflector roll is all located treat that the piece of coating is dorsad one side of coating roll, treat that the piece of coating is installed the surface of first deflector roll with on the surface of second deflector roll, with treat the removal in-process of coating, drive first deflector roll with the second deflector roll rotates.

The first guide roller is provided with a third rotating shaft, the first guide roller can rotate around the third rotating shaft, the second guide roller is provided with a fourth rotating shaft, and the second guide roller can rotate around the fourth rotating shaft; coating device includes the reference direction, the diameter of coating roll on the reference direction is the reference diameter, the coating roll with treat that the tangent line of coating piece at tangent position is public tangent line, the reference diameter with contained angle between the public tangent line is the contact angle, the third axis of rotation can drive first deflector roll is in move on the reference direction, the fourth axis of rotation can drive the second deflector roll is in move on the reference direction, so that the coating roll with treat that the tangent position of coating piece changes, the contact angle changes.

The coating device further comprises an auxiliary roller, an auxiliary rotating shaft is arranged on the auxiliary roller, the auxiliary roller can rotate around the auxiliary rotating shaft, the auxiliary roller is arranged on one side, away from the coating roller, of the metering roller, a second gap is formed between the auxiliary roller and the metering roller, the rotating direction of the auxiliary roller is opposite to that of the metering roller, so that external slurry forms a coating liquid film coated on the metering roller through the second gap, and the coating liquid film on the metering roller and the external slurry form a coating liquid film coated on the coating roller through the first gap.

The coating device further comprises an overflow groove, a feed back groove, a driving piece, a stirring tank and a spray pipe, wherein the coating roller, the metering roller and the auxiliary roller are all partially immersed into the overflow groove, the spray pipe is arranged in the overflow groove and used for spraying slurry into the overflow groove, the feed back groove is sleeved outside the overflow groove and used for receiving slurry overflowing from the overflow groove, the driving piece and the stirring tank are both connected between the feed back groove and the overflow groove, the driving piece is used for conveying the slurry in the feed back groove to the overflow groove, and the stirring tank is used for stirring the slurry.

Wherein the outer surface of the coating roller is in a reticulate pattern; and/or bosses are arranged on the outer surface of the coating roll, the mesh number of the bosses is 10-600 meshes, or concave holes are arranged on the outer surface of the coating roll, the mesh number of the concave holes is 10-600 meshes, or at least one of the concave holes and the bosses is arranged on the outer surface of the coating roll, and the common mesh number of the concave holes and the bosses is 10-600 meshes.

The coating roller comprises a middle part and edge parts arranged on two sides of the middle part, the middle part is in a reticulate pattern shape, a plurality of grooves are arranged on the edge parts, and the grooves are arranged at intervals.

Wherein the diameter of the coating roll is 2cm-60cm, the diameter of the metering roll is 2cm-60cm, and the diameter of the auxiliary roll is 2cm-60 cm; the linear speed of the coating roller is 1m/min-1000m/min, the linear speed of the metering roller is 0.1m/min-10000m/min, and the linear speed of the auxiliary roller is 0.1m/min-10000 m/min.

The concave hole is a round hole, and the diameter of the concave hole is 0.01mm-3 mm; the concave hole is a square hole, and the side length of the concave hole is 0.01mm-3 mm.

In conclusion, the coating liquid film coated on the coating roller is formed through the first gap, the thickness of the coating liquid film can be adjusted by adjusting the size of the first gap, the coating liquid film with the required thickness can be obtained, the phenomenon that the coating liquid film on the coating roller is scraped by a scraper so as to obtain the coating liquid film with the required thickness is avoided, the damage of the scraper to soft particles in the coating liquid film is avoided, the potential safety hazard is avoided, and the quality of the coating liquid film is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

Fig. 1 is a schematic view of a first structure of a coating apparatus provided in an embodiment of the present application.

Fig. 2 is a schematic view of a second structure of a coating apparatus provided in an embodiment of the present application.

Fig. 3 is a front view of the applicator roll of fig. 1.

Fig. 4 is a schematic cross-sectional view of the applicator roll of fig. 3.

Fig. 5 is a schematic view of another cross-sectional structure of the applicator roll of fig. 3.

Fig. 6 is an enlarged schematic view of the tangent position of the coating roll and the piece to be coated in fig. 1.

Fig. 7 is a schematic view of a third structure of a coating apparatus provided in an embodiment of the present application.

Detailed Description

The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative efforts belong to the protection scope of the present invention.

Referring to fig. 1, the present invention provides a coating apparatus for coating a workpiece 3 to be coated, including: the coating roller 1 and the metering roller 2 are arranged, the coating roller 1 is tangent to the piece to be coated 3, a first gap 10 is arranged between the coating roller 1 and the metering roller 2, the coating roller 1 and the metering roller 2 rotate in opposite directions, so that external slurry forms a coating liquid film coated on the coating roller 1 through the first gap 10, and the linear speed direction of the coating roller 1 is opposite to the moving direction of the piece to be coated 3 at the tangent position 30 of the coating roller 1 and the piece to be coated 3, so that the coating liquid film is coated on the piece to be coated 3. In the present application, the member to be coated 3 is a current collector. The current collector may be a lithium ion battery electrode current collector. It is understood that the coating liquid film of the present application may be derived from an ultra-low viscosity slurry system, a soft particle slurry system. The coating liquid film comprises auxiliary material particles.

Thereby, this application forms the coating liquid film of coating on the coating roll 1 through first clearance 10, and can adjust the thickness of coating liquid film through the size of adjusting first clearance 10, can obtain the coating liquid film of required thickness, avoided using the scraper to strike off the coating liquid film on the coating roll 1 in order to obtain the coating liquid film of required thickness, thereby also avoided the damage of the soft granule of scraper in to the coating liquid film, avoided the emergence of potential safety hazard, and promoted the quality of coating liquid film. It will be appreciated that when the flexible particles become damaged they will stick to the applicator roll 1 and metering roll 2 and thicken rapidly, causing rapid friction and pressure heating, which raises safety concerns. The application of the coating device can not damage soft particles and can not generate safety problems.

It will be appreciated that the number of particles in the coating liquid film can be divided by adjusting the speed of the metering roll 2, so that the amount of auxiliary material particles in the coating liquid film can be varied. Specifically, the faster the speed of the metering roll 2 is, the more particles in the coating liquid film are taken away by the metering roll 2, the fewer particles are left on the coating roll 1 at the later stage, and the fewer particles are coated on the piece to be coated 3; the slower the metering roll 2 is, the less particles are taken away by the metering roll 2 in the coating liquid film, the greater the number of particles remaining on the coating roll 1 at a later stage, and the greater the number of particles coated on the member to be coated 3. It is understood that when the speed of the metering roll 2 is changed, or the speed of the applicator roll 1 is changed, or the speed change ratio of the metering roll 2 to the applicator roll 1 is different, the rotation speed ratio of the metering roll 2 to the applicator roll 1 is changed. This application can also realize the regulation of auxiliary material granule volume through the rotational speed ratio of adjusting metering roll 2 and coating roll 1, has solved the scraper and has scraped the technical problem that the auxiliary material granule volume can't be realized to the coating liquid film and has adjusted.

Meanwhile, a first gap 10 is formed between the coating roller 1 and the metering roller 2, namely, the coating roller 1 and the metering roller 2 are in a limit design, so that collision between the coating roller 1 and the metering roller 2 is not possible, particles of slurry are not crushed, safety accidents such as explosion caused by sparks due to collision are avoided, and particularly, the safety of a slurry system of organic solvents such as inflammable and volatile solvents is greatly improved.

In a specific embodiment, the coating roll 1 is provided with a first rotating shaft 40, the coating roll 1 is rotatable around the first rotating shaft 40, the metering roll 2 is provided with a second rotating shaft 50, the metering roll 2 is rotatable around the second rotating shaft 50, and the distance between the first rotating shaft 40 and the second rotating shaft 50 is adjustable, so that the size of the first gap 10 between the coating roll 1 and the metering roll 2 can be adjusted. Specifically, the size of the first gap 10 may control the thickness of the coating liquid film. Accordingly, the present application can control the thickness of the coating liquid film by controlling the size of the first gap 10, thereby forming the coating liquid film having a desired thickness.

It can be understood that the size of the first gap 10 can be adjusted according to the size of the auxiliary material particles, for example, the sum of the diameters of one layer to two layers of auxiliary material particles can be adjusted, so that the thickness of the coating liquid film formed on the coating roller 1 after passing through the first gap 10 can be from one layer to two layers of auxiliary material particles, an ultrathin coating liquid film can be formed on the coating roller 1, and an ultrathin and uniform coating liquid film can be formed on the piece 3 to be coated. The metering roller 2 of the application can not only protect particles, but also adjust the amount of auxiliary material particles better and more precisely.

Referring to fig. 2, in a specific embodiment, the coating apparatus further includes an auxiliary roller 6, the auxiliary roller 6 is provided with an auxiliary rotating shaft 210, the auxiliary roller 6 can rotate around the auxiliary rotating shaft 210, the auxiliary roller 6 is disposed on a side of the metering roller 2 away from the coating roller 1, a second gap 20 is disposed between the auxiliary roller 6 and the metering roller 2, the rotation directions of the auxiliary roller 6 and the metering roller 2 are opposite, so that the external slurry passes through the second gap 20 to form a coating liquid film coated on the metering roller 2, and the coating liquid film on the metering roller 2 and the external slurry together pass through the first gap 10 to form a coating liquid film coated on the coating roller 1. Specifically, the thickness of the coating liquid film may be controlled by the size of the second gap 20, and the thickness of the coating liquid film may be controlled by the rotation speed ratio of the auxiliary roller 6 to the metering roller 2. Therefore, the thickness of the coating liquid film formed on the metering roller 2 can be controlled through the auxiliary roller 6, namely the thickness of the coating liquid film formed on the metering roller 2 can be controlled through the size of the second gap 20 and the rotating speed ratio of the auxiliary roller 6 to the metering roller 2, and further the thickness of the coating liquid film on the coating roller 1 can be controlled more finely so as to meet the coating requirement of higher coating speed.

Referring to fig. 3, in one embodiment, the outer surface of the coating roll 1 is textured 160. Specifically, the coating roll 1 is provided with a flow channel on the outer surface of the reticulate pattern 160, and the flow channel can contain the coating liquid, so that an ultrathin coating liquid film can be formed on the piece 3 to be coated.

Referring to fig. 4, in one embodiment, the outer surface of the applicator roll 1 is provided with bosses 170. The mesh number of the boss 170 is 10-600 meshes. The number of the bosses 170 can satisfy the ultra-thin coating of the coating liquid film.

Referring to fig. 5, in one embodiment, the coating roll 1 has recesses 180 on its outer surface. The mesh number of the concave holes 180 is 10-600 meshes. The concave holes 180 with the mesh number can meet the requirement of ultra-thin coating of the coating liquid film.

In a specific embodiment, the outer surface of the coating roller 1 is provided with at least one of the concave holes 180 and the bosses 170. The common mesh number of the concave holes 180 and the bosses 170 is 10-600 meshes. The concave holes 180 and the bosses 170 with the mesh number can meet the requirement of ultra-thin coating of a coating liquid film.

In one specific embodiment, the recess 180 is a circular hole, and the diameter of the recess 180 is 0.01mm to 3 mm.

In one specific embodiment, the recess 180 is a square hole, with the recess 180 having a side length of 0.01mm to 3 mm.

Therefore, the size of the flow channel volume of the coating roller 1 can be adjusted through the size and the mesh number of the boss 170 and the concave hole 180, the rotating speed of the coating roller 1, the metering roller 2 and the auxiliary roller 6 is combined, the adjustment of different auxiliary material particle quantities can be realized, and the high-speed and ultrathin coating of the slurry is realized. It is understood that the recess 180 may be honeycomb-shaped, and the recess 180 may be a quadrilateral recess 180, a pentagonal recess 180, a hexagonal recess 180, a cylindrical recess 180, etc.; the boss 170 may be a quadrilateral boss 170, a pentagonal boss 170, a hexagonal boss 170, a cylindrical boss 170, or the like. The shapes of the concave hole 180 and the boss 170 are not limited in the present application, except for the above shapes, the boss 170 and the concave hole 180 may have other shapes.

It can be understood that the shape and mesh of the concave holes 180 or the bosses 170 of the coating roller 1 can affect the number of the auxiliary material particles, and the mesh and shape of the concave holes 180 or the bosses 170 can meet the requirement of ultra-thin coating of the coating liquid film.

The coating device further comprises a first guide roller 4 and a second guide roller 5, the first guide roller 4 and the second guide roller 5 are both arranged on one side, opposite to the coating roller 1, of the piece 3 to be coated, and the piece 3 to be coated is arranged on the outer surface of the first guide roller 4 and the outer surface of the second guide roller 5, so that the first guide roller 4 and the second guide roller 5 are driven to rotate in the moving process of the piece 3 to be coated. It can be understood that the piece to be coated 3 can be driven to move by an external traction structure, the piece to be coated 3 drives the first guide roller 4 and the second guide roller 5 to rotate, the first guide roller 4 and the second guide roller 5 can be used as support rollers for the piece to be coated 3, and the piece to be coated 3 can stably move on the first guide roller 4 and the second guide roller 5.

Specifically, the first guide roller 4 and the second guide roller 5 rotate in the same direction to drive the piece to be coated 3 to move, the rotation directions of the coating roller 1, the first guide roller 4 and the second guide roller 5 are opposite, so that at the tangent position of the coating roller 1 and the piece to be coated 3, the linear velocity direction of the coating roller 1 is opposite to the movement direction of the piece to be coated 3, and a liquid film to be coated on the coating roller 1 can be coated on all surfaces of the piece to be coated 3.

Therefore, the coating roller 1 can coat the coating liquid film on all the surfaces of the piece to be coated 3 in the moving process of the piece to be coated 3 by driving the piece to be coated 3 to move through the rotation of the first guide roller 4 and the second guide roller 5.

In a specific embodiment, the applicator roll 1 rotates clockwise, the metering roll 2 rotates counterclockwise, the backup roll 6 rotates clockwise, the first guide roll 4 rotates clockwise, and the second guide roll 5 rotates clockwise.

Referring to fig. 1-2, the first guide roller 4 is provided with a third rotation axis 60, the first guide roller 4 can rotate around the third rotation axis 60, the second guide roller 5 is provided with a fourth rotation axis 70, and the second guide roller 5 can rotate around the fourth rotation axis 70.

Referring to fig. 6, the coating apparatus includes a reference direction X, a diameter of the coating roller 1 in the reference direction X is a reference diameter 220, a tangent line of the coating roller 1 and the workpiece 3 to be coated at the tangent position 30 is a common tangent line 80, an included angle between the reference diameter 220 and the common tangent line 80 is a contact angle 90, the third rotating shaft 60 can drive the first guide roller 4 to move in the reference direction X, and the fourth rotating shaft 70 can drive the second guide roller 5 to move in the reference direction X, so that the tangent position 30 of the coating roller 1 and the workpiece 3 to be coated changes, and the contact angle 90 changes. In particular, in different coating applications, in order to avoid mutual compression between the coating roller 1 and the piece to be coated 3, the tangent position 30 between the coating roller 1 and the piece to be coated 3 needs to be changed, and the contact angle 90 between the reference diameter 220 and the common tangent 80 is changed along with the change of the tangent position 30 so as to avoid mutual compression between the coating roller 1 and the piece to be coated 3. Thus, the change of the contact angle 90 can avoid mutual extrusion between the coating roller 1 and the piece 3 to be coated in different occasions. In the present application, the reference direction X is a horizontal direction shown in fig. 6. It is understood that the movement of the third rotating shaft 60 in the reference direction X is the movement of the third rotating shaft 60 in the horizontal direction, and the movement of the fourth rotating shaft 70 in the reference direction X is the movement of the fourth rotating shaft 70 in the horizontal direction.

With continued reference to fig. 6, the contact angle 901 of the reference diameter 220 and the common tangent line 80 at the first tangent position 301 is larger than the contact angle 902 of the reference diameter 220 and the common tangent line 80 at the second tangent position 302, and the coating roller 1 and the member to be coated 3 are not pressed at the first tangent position 301 and the second tangent position 302. That is, with the change of the tangent position 30, the following change of the contact angle 902 can prevent the coating roller 1 from pressing against the member to be coated 3, and avoid the damage of the flexible particles.

In one particular embodiment, the contact angle 90 varies from 20 to 180 °.

It will be appreciated that, in addition to the shape and mesh of the recesses 180 or bosses 170 of the coating roll 1, the rotational speed of the coating roll 1 and the speed of the piece 3 to be coated, which can affect the number of auxiliary material particles, the compression between the coating roll 1 and the piece 3 to be coated also affects the number of auxiliary material particles. In particular, if the pressing force between the coating roller 1 and the piece 3 to be coated is large, there is a risk of damaging the soft granules and the number of auxiliary material granules decreases. This application can avoid coating roll 1 and treat the extrusion between the coating piece 3 through the size of adjusting contact angle 90, avoids the damage of auxiliary material granule, and the auxiliary material granule volume can not reduce. Therefore, the position of the first guide roller 4 and the second guide roller 5 is adjusted, so that the coating roller 1 slightly contacts with the piece to be coated 3 in the tangential direction, and the extrusion damage of the coating roller 1 to soft particles in the slurry can be avoided.

In a particular embodiment, the diameter of the applicator roll 1 is between 2cm and 60 cm; the diameter of the metering roller 2 is 2cm-60 cm; the diameter of the auxiliary roller 6 is 2cm-60 cm.

In a specific embodiment, the linear speed of the coating roll 1 is 1m/min to 1000 m/min; the linear speed of the metering roller 2 is 0.1m/min-10000 m/min; the linear velocity of the auxiliary roller 6 is 0.1m/min-10000 m/min.

In a specific embodiment, the coating roller 1 comprises a middle part 11 and edge parts 12 arranged at two sides of the middle part 11, the middle part 11 is in a reticulate pattern, the edge parts 12 are provided with a plurality of grooves 190, and the grooves 190 are arranged at intervals. Specifically, middle part 11 is used for treating to scribble the coating 3, and edge part 12 is idle region, and a plurality of recesses 190 that edge part 12 set up can stir uncoated thick liquids at coating roller 1 pivoted in-process, and then can make the auxiliary material granule misce bene in the thick liquids, and difficult gathering and caking can be used for the even coating of unstable thick liquids system, also do benefit to the dispersion of thick liquids simultaneously. It will be appreciated that the grooves 190 of the rim portion 12 may be machined to resemble a waterwheel pattern of grooves 190 that provide some agitation to the slurry.

Referring to fig. 7, the coating apparatus further includes an overflow tank 110, a material return tank 120, a driving member 130, a stirring tank 140, and a spray pipe 150, wherein the coating roller 1, the metering roller 2, and the auxiliary roller 6 are all partially immersed in the overflow tank 110, the spray pipe 150 is disposed in the overflow tank 110 and is used for spraying the slurry into the overflow tank 110, the material return tank 120 is sleeved outside the overflow tank 110 and is used for receiving the slurry overflowing from the overflow tank 110, the driving member 130 and the stirring tank 140 are both connected between the material return tank 120 and the overflow tank 110, the driving member 130 is used for conveying the slurry in the material return tank 120 to the overflow tank 110, and the stirring tank 140. Specifically, in the process of spraying the slurry by the spray pipe 150, not only a certain stirring effect can be exerted on the slurry, but also the flow rate of the feeding material can be increased, so that the slurry continuously overflows the overflow groove 110 and flows back into the feed-back groove 120, the slurry in the feed-back groove 120 can enter the overflow groove 110 in a dispersed state through the stirring effect of the stirring tank 140 and the driving effect of the driving element 130, and the auxiliary roll 6, the metering roll 2 and the coating roll 1 can suck the slurry, and after the coating roll 1, the metering roll 2 and the auxiliary roll 6 suck the slurry from the overflow groove 110, a coating liquid film on the to-be-coated piece 3 can be formed.

Therefore, the groove 190, the stirring tank 140 and the spray pipe 150 of the edge part 12 can stir the slurry, so that the auxiliary material particles in the slurry are uniformly dispersed and are not easy to gather and agglomerate, and a uniform coating effect can be provided for some unstable slurry systems.

Under the combined action of the above-mentioned coating devices, it is possible to form 0.1-10g/m on the piece 3 to be coated²The uniform coating liquid film has no damage to particles in the coating liquid film, and is safe and reliable.

The technical features of the above embodiments may be arbitrarily combined, and for the sake of brief description, all possible combinations of the technical features in the above embodiments are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features.

The above examples only represent some embodiments of the present invention, and the description thereof is more specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A coating apparatus for coating a member to be coated, comprising: the coating roll and the metering roll are tangent to each other, a first gap is arranged between the coating roll and the metering roll, the coating roll and the metering roll rotate in opposite directions, so that external slurry passes through the first gap to form a coating liquid film coated on the coating roll, and the linear velocity direction of the coating roll is opposite to the moving direction of the piece to be coated at the tangent position of the coating roll and the piece to be coated, so that the coating liquid film on the coating roll is coated on the piece to be coated.

2. The coating apparatus according to claim 1, wherein the coating roll is provided with a first rotating shaft, the coating roll is rotatable about the first rotating shaft, the metering roll is provided with a second rotating shaft, the metering roll is rotatable about the second rotating shaft, and a distance between the first rotating shaft and the second rotating shaft is adjustable so that a size of a first gap between the coating roll and the metering roll is adjustable.

3. The coating apparatus as claimed in claim 1, further comprising a first guide roller and a second guide roller, wherein the first guide roller and the second guide roller are both disposed on a side of the workpiece to be coated opposite to the coating roller, and the workpiece to be coated is disposed on an outer surface of the first guide roller and an outer surface of the second guide roller, so as to drive the first guide roller and the second guide roller to rotate during the movement of the workpiece to be coated.

4. The coating apparatus as claimed in claim 3, wherein a third rotation axis is provided on the first guide roller, the first guide roller being rotatable about the third rotation axis, a fourth rotation axis is provided on the second guide roller, the second guide roller being rotatable about the fourth rotation axis; coating device includes the reference direction, the diameter of coating roll on the reference direction is the reference diameter, the coating roll with treat that the tangent line of coating piece at tangent position is public tangent line, the reference diameter with contained angle between the public tangent line is the contact angle, the third axis of rotation can drive first deflector roll is in move on the reference direction, the fourth axis of rotation can drive the second deflector roll is in move on the reference direction, so that the coating roll with treat that the tangent position of coating piece changes, the contact angle changes.

5. The coating apparatus as claimed in claim 1, further comprising an auxiliary roller having an auxiliary rotating shaft, the auxiliary roller being rotatable around the auxiliary rotating shaft, the auxiliary roller being disposed on a side of the metering roller away from the coating roller, a second gap being provided between the auxiliary roller and the metering roller, the auxiliary roller and the metering roller being rotated in opposite directions so that the external slurry passes through the second gap to form a coating liquid film coated on the metering roller, and the coating liquid film on the metering roller and the external slurry together pass through the first gap to form a coating liquid film coated on the coating roller.

6. The coating apparatus as claimed in claim 5, further comprising an overflow tank, a material returning tank, a driving member, an agitator tank, and a spraying pipe, wherein the coating roller, the metering roller, and the auxiliary roller are all partially immersed in the overflow tank, the spraying pipe is disposed in the overflow tank for spraying the slurry to the overflow tank, the material returning tank is sleeved outside the overflow tank for receiving the slurry overflowing from the overflow tank, the driving member and the agitator tank are both connected between the material returning tank and the overflow tank, the driving member is used for conveying the slurry in the material returning tank to the overflow tank, and the agitator tank is used for agitating the slurry.

7. The coating apparatus of claim 1, wherein the outer surface of the coating roller is textured; and/or bosses are arranged on the outer surface of the coating roll, the mesh number of the bosses is 10-600 meshes, or concave holes are arranged on the outer surface of the coating roll, the mesh number of the concave holes is 10-600 meshes, or at least one of the concave holes and the bosses is arranged on the outer surface of the coating roll, and the common mesh number of the concave holes and the bosses is 10-600 meshes.

8. The coating apparatus as claimed in claim 1, wherein the coating roller includes a middle portion and edge portions provided on both sides of the middle portion, the middle portion having a textured shape, the edge portions having a plurality of grooves provided thereon, the plurality of grooves being provided at intervals.

9. The coating apparatus of claim 5, wherein the diameter of the coating roll is 2cm to 60cm, the diameter of the metering roll is 2cm to 60cm, and the diameter of the auxiliary roll is 2cm to 60 cm; the linear speed of the coating roller is 1m/min-1000m/min, the linear speed of the metering roller is 0.1m/min-10000m/min, and the linear speed of the auxiliary roller is 0.1m/min-10000 m/min.

10. The coating apparatus of claim 7, wherein the recesses are round holes, the recesses having a diameter of 0.01mm to 3 mm; the concave hole is a square hole, and the side length of the concave hole is 0.01mm-3 mm.