CN220129748U - Scraper device and silk screen coating equipment - Google Patents

Abstract

The utility model discloses a scraper device and screen coating equipment, wherein the scraper device at least comprises an ink returning knife, a scraper and an ink adding assembly, the ink adding assembly comprises a discharging piece, a plurality of discharging holes are formed in the discharging piece, all the discharging holes are distributed at intervals along the length direction of the discharging piece, the discharging piece is a separately arranged part, and the discharging piece is fixedly arranged on the ink returning knife and can synchronously move along with the ink returning knife, or the discharging piece and the ink returning knife are integrally arranged. When the ink returning operation is carried out by translating the ink returning knife, a plurality of discharging holes on the discharging plate are used for simultaneously coating the sizing agent on the printing screen, so that the sizing agent can be uniformly coated and the ink returning times can be reduced.

Description

Scraper device and silk screen coating equipment

Technical Field

The utility model relates to the field of photovoltaic cell production, in particular to a scraper device and silk screen coating equipment with the same.

Background

In the prior art, electrodes of the photovoltaic cell are mostly manufactured by screen printing, wherein silver paste is penetrated through a printing screen by a screen printer to form silver grid lines on the photovoltaic cell. In recent years, a metal electrode of a photovoltaic cell manufactured by an electroplating method has been used in mass production of the photovoltaic cell, in the process of the production, photosensitive ink is coated on the surface of the photovoltaic cell by a doctor blade device to form a mask layer, and then the mask layer is etched by laser to form a mask opening, so that the metal electrode is used for subsequent electroplating processing to form a grid line electrode on the photovoltaic cell.

The existing scraper device comprises a scraper and an ink returning knife, during screen printing, printing paste is generally added to the first end of a printing screen, and then the ink returning knife moves from the first end of the printing screen to the second end of the printing screen in a reciprocating translational motion for a plurality of times, so that the paste is uniformly coated on the printing screen; finally, the scraper moves from the second end to the first end, and the slurry on the printing screen is extruded onto the photovoltaic cell through the mesh holes on the printing screen. In the above process, the printing paste is usually applied by manual intermittent inking, and the ink (photosensitive ink, also called photoresist) needs to be applied periodically and quantitatively by special personnel, which causes the following problems: 1. the ink can be manually added only by stopping the machine, so that the production efficiency of the equipment is reduced; 2. the labor cost is increased; 3. in general, the ink return knife needs to reciprocate for multiple times to uniformly coat the paste on the printing screen, and if the viscosity of the paste is low, the paste leakage state may occur in the process of reciprocating the ink return knife for multiple times, so that the printing quality is affected.

It should be noted that the foregoing background is only for the purpose of aiding in the understanding of the inventive concepts and technical aspects of the present application and is not necessarily prior art to the present application, and should not be used to evaluate the novelty or creativity of the present utility model in the event that no clear evidence indicates that such an aspect has been disclosed prior to the filing date of the present application.

Disclosure of Invention

It is an object of the present utility model to provide a new doctor apparatus which solves one or more of the problems of the prior art.

In order to achieve the above purpose, the technical scheme adopted by the embodiment of the utility model is as follows: the utility model provides a scraper device, includes scraper and back black sword at least, scraper device still includes the inking subassembly, the inking subassembly includes the ejection of compact piece, the ejection of compact piece is fixedly set up on the back black sword and can follow back black sword synchronous motion, be provided with a plurality of discharge holes on the ejection of compact piece, all the discharge hole is followed the length direction interval distribution of ejection of compact piece, the ejection of compact piece is a part that singly sets up, the ejection of compact piece is fixedly set up on the back black sword and can follow back black sword synchronous motion, perhaps ejection of compact piece and back black sword an organic whole set up.

Preferably, the discharging part is provided with a hollow material cavity, the discharging hole is communicated with the material cavity, the inking component further comprises a connecting pipe, the connecting pipe is provided with a first end part and a second end part which are respectively arranged at two different ends in the length direction of the connecting pipe, the first end part is connected to the discharging part, and the pipe cavity of the connecting pipe is communicated with the material cavity.

In some embodiments, the second end is vertically higher than the first end, and the second end is provided with a connector for connecting with an external feeding device.

In some embodiments, the discharging part comprises a discharging plate and a storage seat, the discharging plate is fixedly arranged on one side of the storage seat, a material cavity is formed between the discharging plate and the storage seat, and the discharging hole is formed in the discharging plate and penetrates through the discharging plate along the thickness direction of the discharging plate.

In some embodiments, the discharge plate is fixedly disposed on the ink return blade, a top of the storage seat has a fill port, and the first end is connected in the fill port.

In some embodiments, all the discharging holes are uniformly spaced in the length extending direction of the discharging member, and the distance between the two outermost discharging holes in the length extending direction of the discharging member is smaller than the length of the ink return knife.

In some embodiments, the bottom surface of the ink outlet member is vertically higher than the bottom surface of the ink return blade, and/or all orthographic projections of the discharge holes on the side surface of the ink return blade, which is close to the side of the ink outlet member, fall on the side surface of the ink return blade, which is close to the side of the ink outlet member.

In some embodiments, at least a portion of the ink return blade is positioned in the discharge path of the slurry flowing out through the discharge orifice; or, the scraper device further comprises a guide plate arranged between the ink returning knife and the discharging piece, and at least part of the guide plate is positioned on the discharging path of the slurry flowing out through the discharging hole.

In some embodiments, the discharging hole is in contact with the ink returning knife, or the discharging hole is in contact with the guide plate, wherein the guide plate is fixedly arranged on the ink returning knife, and the lowest point of the guide plate is higher than the knife edge of the ink returning knife.

In some embodiments, the doctor device further includes a doctor, a length extending direction of the doctor is parallel to a length extending direction of the ink return blade, the doctor and the ink return blade are arranged at intervals along a preset translation direction, the translation direction is perpendicular to the length direction of the ink return blade, and the discharging piece is arranged between the doctor and the ink return blade.

In some embodiments, the doctor device further includes a mount, and the doctor and the ink return blade are each provided on the mount so as to be capable of being lifted in a vertical direction.

In some embodiments, the ink adding assembly further comprises a connecting pipe, wherein the connecting pipe comprises a first connecting pipe and a plurality of second connecting pipes which are connected and communicated with the first connecting pipe, and the plurality of second connecting pipes are connected with the plurality of discharging holes in a one-to-one correspondence manner; or, the inking component further comprises a plurality of second connecting pipes, one ends of the second connecting pipes are connected with and communicated with an external feeding device, and the other ends of the second connecting pipes are connected with the discharging holes in a one-to-one correspondence manner.

In some embodiments, a flow valve is disposed on the second connecting tube; and/or, the pipe diameters of the plurality of second connecting pipes are different; and/or the apertures of the plurality of discharging holes are different.

Another object of the present utility model is to provide a screen coating apparatus.

In order to achieve the above purpose, the technical scheme adopted by the embodiment of the utility model is as follows: a screen coating apparatus comprising a doctor blade device as described above.

Due to the application of the technical scheme, compared with the prior art, the embodiment of the utility model has the following advantages: according to the scraper device provided by the embodiment of the utility model, the discharging piece of the inking component is fixedly arranged on the ink returning knife and can synchronously move along with the ink returning knife, and in the process of ink returning operation by translating the ink returning knife, the plurality of discharging holes on the discharging plate are used for coating the sizing agent on the printing screen, so that the sizing agent can be uniformly coated, the ink returning times can be effectively reduced, meanwhile, the sizing agent can be automatically added through the feeding device in the process of printing processing, the stop and the manual intervention are not needed, the production efficiency and the printing quality of the silk screen coating equipment can be effectively improved, and the labor cost is saved.

Drawings

FIG. 1 is a schematic diagram of the overall structure of a doctor apparatus according to an embodiment of the present utility model;

FIG. 2 is a front view of the doctor apparatus of FIG. 1;

FIG. 3 is a side view of the doctor apparatus of FIG. 1;

FIG. 4 is a schematic view of the overall structure of the inking assembly of the doctor apparatus of FIG. 1;

FIG. 5 is a front view of the inking assembly of FIG. 4;

FIG. 6 is a schematic longitudinal cross-sectional view of the inking assembly of FIG. 4;

FIG. 7 is a side view of the inking assembly of FIG. 4;

FIG. 8 is a schematic view of a second construction of an ink assembly according to an embodiment of the present utility model;

FIG. 9 is a schematic view of a third construction of an inking assembly according to an embodiment of the present utility model;

wherein: 10. a mounting base; 1. ink returning knife; 2. a scraper; 3. a first base; 4. a first lifting driving device; 5. a second seat body; 6. a second lifting driving device; 7. an inking assembly; 71. a discharging piece; 711. a discharge plate; 712. a material storage seat; 71a, a discharge hole; 71b, a material cavity; 71c, a material injection port; 72. a connecting pipe; 721. a first end; 722. a second end; 723. a first connection pipe; 724. a second connection pipe; 725. a flow valve; 73. and (3) a joint.

Detailed Description

The technical scheme of the utility model is further described below with reference to the attached drawings and specific embodiments.

Example 1

Referring to the doctor apparatus shown in fig. 1 to 3, the doctor apparatus includes an ink return blade 1 and a doctor blade 2, wherein a length extending direction of the ink return blade 1 and a length extending direction of the doctor blade 2 are parallel to each other, and are arranged at intervals in a preset translation direction of the doctor apparatus, and the preset translation direction is perpendicular to the length extending direction of the ink return blade 1/the doctor blade 2. Here, the length extending direction of the ink returning knife 1/the doctor blade 2 is defined as the X direction, the ink returning knife 1 and the doctor blade 2 are spaced apart in the Y direction, and the doctor device translates along the Y direction when working, that is, the predetermined translation direction is the Y direction.

The doctor device further comprises a mounting seat 10, the upper part of the ink returning knife 1 is connected with a first seat body 3, the upper part of the doctor 2 is connected with a second seat body 5, the first seat body 3 and the second seat body 5 can be respectively arranged on the mounting seat 10 in a sliding manner along the vertical direction, a first lifting driving device 4 for driving the first seat body 3 to lift along the vertical direction and a second lifting driving device 6 for driving the second seat body 5 to lift along the vertical direction are further arranged on the upper part of the mounting seat 10, and the first lifting driving device 4 and the second lifting driving device 6 are cylinders or linear motors so as to respectively drive the ink returning knife 1 and the doctor 2 to lift along the Z direction.

Referring to fig. 1 to 7, the doctor apparatus further includes an inking assembly 7, and the inking assembly 7 includes a discharging member 71, and the discharging member 71 is disposed on the ink return blade 1 and is capable of moving synchronously with the ink return blade 1, and the synchronous movement includes, but is not limited to, lifting movement in the Z direction and translational movement in the Y direction. The length extending direction of the discharging member 71 is parallel to the length extending direction of the ink returning knife 1, i.e. the discharging member 71 extends along the X direction; the discharging member 71 is provided with a hollow material cavity 71b, the discharging member 71 is further provided with a plurality of discharging holes 71a, all the discharging holes 71a are communicated with the material cavity 71b, and all the discharging holes 71a are distributed at intervals along the length extending direction of the discharging member 71.

The ink adding unit 7 further includes a connection pipe 72 and a joint 73, the connection pipe 72 has a first end 721 and a second end 722 which are respectively provided at different ends in a longitudinal direction thereof, the first end 721 is connected to the discharging member 71 and a lumen of the connection pipe 72 communicates with the material chamber 71b, the second end 722 is vertically higher than the first end 721, and the joint 73 is provided at the second end 722 for connection with an external feeding device (not shown) so as to inject slurry into the material chamber 71b through the connection pipe 72. In the operating state, the slurry flows into the cavity 71b from the external supply device via the connection pipe 72, is extruded into the discharge hole 71a from the cavity 71b, and flows out (including spouting) from the hole 71a. On the one hand, the slurry is buffered in the material cavity 71b, and in a state that the external feeding device is short in material shortage, the material cavity 71b can continue to discharge, so that the external feeding device has a certain reaction time to complete feeding. On the other hand, the material chamber 71b, which serves as an equal pressure point, can provide the same or similar pressure to the slurry flowing into the plurality of discharge holes 71a, so that the flow rate of the slurry flowing out of the plurality of discharge holes 71a remains the same or similar, i.e., so that the slurry flowing out of the plurality of discharge holes 71a remains uniform, and the slurries flowing out of the plurality of discharge holes 71a can be uniformly applied to each other on the printing screen.

Referring to fig. 4 to 6, in the present embodiment, the discharging member 71 includes a discharging plate 711 and a storage seat 712, the discharging plate 711 is fixedly disposed on one side of the storage seat 712, the above-mentioned material cavity 71b is formed between the discharging plate 711 and the storage seat 712, all the discharging holes 71a are disposed on the discharging plate 711 and penetrate the discharging plate 711 along the thickness direction of the discharging plate 711 to communicate with the material cavity 71b, and meanwhile, the height of the discharging hole 71a along the vertical direction on the discharging plate 711 is close to the bottom position of the material cavity 71 b.

The height of the discharging plate 711 is larger than that of the storage seat 712, the discharging plate 711 is fixedly arranged on the ink return knife 1, the longitudinal section of the storage seat 712 is approximately triangular, the top of the storage seat is provided with a material injection hole 71c, and the first end 721 of the connecting pipe 72 is fixedly connected in the material injection hole 71 c.

All the discharge holes 71a are arranged at uniform intervals in the length extending direction of the discharge member 71, the distance between the two outermost discharge holes 71a in the length extending direction of the discharge member 71 is smaller than the length of the ink return blade 1, and at the same time, both ends of the discharge member 71 are located inside the ink return blade 1 in the length extending direction of the ink return blade 1, that is, the orthographic projection of all the discharge holes 71a on the side of the ink return blade 1 near the discharge member 71 falls on the side of the ink return blade 1 near the discharge member 71. In this way, on the one hand, it is ensured that the size in the X-direction formed when the paste flowing out of the discharge member 71 falls on the printing screen (not shown in the drawing) is smaller than the length of the ink return blade 1; on the other hand, the paste falling on the printing screen can be contacted by the ink returning knife 1, so that the paste can be uniformly coated on the printing screen from the middle to the two sides along the X direction under the action of the ink returning knife 1.

Further, as shown in fig. 1 to 3, the bottom surface of the discharging member 71 is higher than the bottom surface of the ink returning blade 1 in the vertical direction, and when the ink returning blade 1 is cooperated with the printing screen to return ink, the discharging member 71 is suspended above the printing screen without being in contact with the printing screen. The discharging member 71 is located between the doctor blade 2 and the ink return blade 1 in the Y direction.

In the doctor device of this embodiment, a plurality of discharge holes 71a are disposed on the discharge member 71, and all the discharge holes 71a are uniformly spaced along the length extension direction of the ink return knife 1, meanwhile, the discharge member 71 is synchronously lifted and translated along with the ink return knife 1, in the ink return process, the distance H between the discharge holes 71a and the printing screen along the Z direction is a fixed value, in unit time, the slurry with the same volume V is coated on the printing screen through the plurality of discharge holes 71a, so that the width of the slurry coated on the printing screen at a time is larger, uniform coating of the slurry can be realized, the ink return times can be effectively reduced, the ink return process can be completed even once after fewer times, the printing process can be realized by matching the doctor 2 with the printing screen, and the printing process can be seamless, and the printing processing efficiency can be remarkably improved.

The screen coating apparatus using the doctor blade device further includes a feeding device and a control device, wherein the feeding device is connected to the connecting pipe 72 through the joint 73 and is used for injecting slurry into the cavity 71b of the discharging member 71, and the control device is mainly used for controlling the working state of the feeding device and is used for controlling the flow rate, the flow velocity and the time node of injecting slurry into the cavity 71 b.

In the screen coating apparatus of this embodiment, when performing screen printing, the ink return knife 1 is first lowered down along Z and cooperates with the printing screen, the feeding device injects slurry into the material chamber 71b of the discharging member 71, and in the process of the overall translational movement of the doctor device along the Y direction, the slurry in the material chamber 71b flows from the plurality of discharging holes 71a onto the printing screen below, and then the ink return knife 1 uniformly coats the slurry on the printing screen. Wherein the control device supplies the paste to the discharging member 71 according to the required paste amount, and before the ink returning knife 1 reaches the other end from one end of the printing screen in the Y direction, all the paste flows onto the printing screen through all the discharging holes 71a. After the ink returning knife 1 reaches the other end from one end of the printing screen along the Y direction, the ink returning knife 1 ascends along the Z direction, and the scraper 2 descends along the Z direction to be matched with the printing screen for printing processing.

In other embodiments, the ink return blade 1 descends downward along Z and cooperates with the printing screen, the feeding device injects the slurry into the material cavity 71b of the discharging member 71, the slurry in the material cavity 71b flows onto the ink return blade 1 from the plurality of discharging holes 71a during the translational movement of the whole doctor device along the Y direction, and the ink return blade 1 then uniformly coats the slurry on the printing screen after guiding the slurry flowing onto the printing screen via the ink return blade 1. Wherein the control device supplies the paste to the discharging member 71 according to the required paste amount, and before the ink returning knife 1 reaches the other end from one end of the printing screen in the Y direction, all the paste flows onto the printing screen through all the discharging holes 71a. After the ink returning knife 1 reaches the other end from one end of the printing screen along the Y direction, the ink returning knife 1 ascends along the Z direction, and the scraper 2 descends along the Z direction to be matched with the printing screen for printing processing.

In other embodiments, a baffle (not shown) is disposed between the discharging member 71 and the ink returning knife 1, one end of the discharging hole 71a is connected to the material cavity 71b, the other end of the discharging hole 71a contacts the baffle, the ink returning knife 1 descends down along Z and cooperates with the printing screen, the feeding device injects slurry into the material cavity 71b of the discharging member 71, during the translational movement of the whole doctor device along the Y direction, the slurry in the material cavity 71b flows from the plurality of discharging holes 71a onto the baffle, and is guided to flow onto the printing screen below by the baffle, and the ink returning knife 1 then uniformly coats the slurry on the printing screen. Wherein the control device supplies the paste to the discharging member 71 according to the required paste amount, and before the ink returning knife 1 reaches the other end from one end of the printing screen in the Y direction, all the paste flows onto the printing screen through all the discharging holes 71a. After the ink returning knife 1 reaches the other end from one end of the printing screen along the Y direction, the ink returning knife 1 ascends along the Z direction, and the scraper 2 descends along the Z direction to be matched with the printing screen for printing processing. The guide plate can be fixedly arranged on the ink return knife 1, and the lowest point of the guide plate is higher than the knife edge of the ink return knife 1.

In summary, in the printing process, the automatic slurry adding can be realized, the shutdown and the manual intervention are not needed when the slurry is added, the production efficiency of the silk screen coating equipment can be effectively improved, the labor cost is saved, meanwhile, the slurry is discharged at multiple points in the length extension direction of the ink return knife 1, the ink return knife 1 can uniformly coat the slurry on the printing screen plate only by a small amount of times or even by one translational movement, the printing efficiency is improved, and meanwhile, the phenomenon that the printing quality is influenced due to the slurry leakage state in the long-time reciprocating motion process is avoided.

Example 2

Unlike embodiment 1, the discharging member 71 and the ink return blade 1 are integrally provided, and the ink return blade 1 simultaneously constitutes the discharging member 71.

Referring to fig. 1 to 7, the doctor apparatus includes an ink return blade 1, a doctor blade 2, and an ink-applying assembly 7, and the ink-applying assembly 7 includes a discharging member 71 (which can be understood as a partial structure of the ink return blade 1). The length extension direction of the discharging member 71 is the same as the length extension direction of the blade edge of the ink return blade 1, that is, both extend in the X direction. The discharging member 71 has a hollow material cavity 71b, and the discharging member 71 is further provided with a plurality of discharging holes 71a, all the discharging holes 71a are communicated with the material cavity 71b, and all the discharging holes 71a are distributed at intervals along the length extending direction of the discharging member 71, preferably at equal intervals.

The ink adding unit 7 further includes a connection pipe 72 and a joint 73, the connection pipe 72 has a first end 721 and a second end 722 which are disposed at different ends in a longitudinal direction thereof, the first end 721 is connected to the discharging member 71 and a lumen of the connection pipe 72 communicates with the material chamber 71b, the second end 722 may be higher than the first end 721 in a vertical direction, and the joint 73 is disposed on the second end 722 for connection with an external feeding device (not shown) so as to inject slurry into the material chamber 71b through the connection pipe 72. In the operating state, the slurry flows from the external supply device into the cavity 71b via the connection pipe 72, is extruded from the cavity 71b into the discharge hole 71a, and flows out from the hole 71a. On the one hand, the slurry is buffered in the material cavity 71b, and in a state that the external feeding device is short in material shortage, the material cavity 71b can continue to discharge, so that the external feeding device has a certain reaction time to complete feeding. On the other hand, the material chamber 71b, which serves as an equal pressure point, can provide the same or similar pressure to the slurry flowing into the plurality of discharge holes 71a, so that the flow rate of the slurry flowing out of the plurality of discharge holes 71a remains the same or similar, i.e., so that the slurry flowing out of the plurality of discharge holes 71a remains uniform, and the slurries flowing out of the plurality of discharge holes 71a can be uniformly applied to each other on the printing screen.

The other structures and technical solutions in embodiment 1 may be applied to embodiment 2 without departing from the principle of embodiment 2.

Example 3

The conversion was performed on the basis of example 1 or example 2 to form a new doctor blade apparatus, as shown in fig. 8 and 9, comprising a return blade 1, a doctor blade 2, and an inking assembly 7, the inking assembly 7 comprising a discharge element 71. The length extending direction of the discharging member 71 is the same as or parallel to the length extending direction of the blade edge of the ink return blade 1, that is, both extend in the X direction. The discharge member 71 is provided with a plurality of discharge holes 71a, and all the discharge holes 71a are distributed at intervals, preferably at equal intervals, along the length extending direction of the discharge member 71.

In the first implementation of the present embodiment, the ink adding assembly further includes a connection pipe 72 including a first connection pipe 723 and a plurality of second connection pipes 724 connected to and communicating with the first connection pipe 723, the plurality of second connection pipes 724 being connected to the plurality of discharge holes 71a in one-to-one correspondence. Unlike embodiment 1 and embodiment 2, the structure of the material chamber 71b is omitted in embodiment 3, and a plurality of discharge holes 71a are directly connected in one-to-one correspondence through a plurality of second connection pipes 724.

Because of the difference in the pipe structure and/or the difference in the pressure of the feed, the discharge of each discharge hole 71a is liable to be inconsistent (the flow rate or flow velocity of the discharge is inconsistent). To solve the uniformity of the discharge of each discharge hole 71a (the flow rate or flow velocity of the discharge is kept uniform), the following scheme or combination thereof may be adopted: first, a flow valve 725 is provided in each second connection pipe 724, and the flow rate of the slurry in each second connection pipe 724 is controlled by the flow valve 725. Secondly, the pipe diameters of the second connecting pipes 724 are set according to the requirement, so that the pipe diameters of the second connecting pipes 724 are different, and the flow rate or the flow velocity of the slurry in the second connecting pipes 724 is kept consistent. Thirdly, the aperture of each discharge hole 71a is set according to the requirement, so that the apertures of the plurality of discharge holes 71a are different, and the flow rate or the flow velocity of the slurry in each discharge hole 71a is kept consistent. By the above scheme or the combination thereof, the pastes flowing out of the plurality of discharging holes 71a can be uniformly coated on the printing screen with each other. Illustratively, when the apertures of the discharge holes 71a are the same and are arranged at equal intervals, the flow rate of the slurry in each discharge hole 71a can be controlled to be uniform; when the discharge holes 71a are arranged at unequal intervals and the diameters of the holes are different, the flow rate of the slurry in each discharge hole 71a can be controlled to be uniform.

In the second implementation manner of this embodiment, the ink adding assembly 7 further includes a plurality of second connection pipes 724, one ends of the second connection pipes 724 are connected to and communicate with the external feeding device, and the other ends of the second connection pipes 724 are connected to the plurality of discharge holes 71a in a one-to-one correspondence.

Example 4

The main improvement of the silk screen coating equipment is a scraper device, and the scraper device adopts the technical scheme formed by any one embodiment or combination of any two or more embodiments in embodiments 1-3.

The above embodiments are provided to illustrate the technical concept and features of the present utility model and are intended to enable those skilled in the art to understand the content of the present utility model and implement the same, and are not intended to limit the scope of the present utility model. All equivalent changes or modifications made in accordance with the spirit of the present utility model should be construed to be included in the scope of the present utility model.

Claims (14)

1. A doctor apparatus comprising at least a doctor and an ink return blade, characterized in that: the scraper device further comprises an inking component, the inking component comprises a discharging part, a plurality of discharging holes are formed in the discharging part, all discharging holes are distributed at intervals along the length direction of the discharging part, the discharging part is a part which is arranged independently, and the discharging part is fixedly arranged on the ink return knife and can move synchronously with the ink return knife, or the discharging part and the ink return knife are integrally arranged.

2. Doctor apparatus according to claim 1, characterized in that: the discharging piece is provided with a hollow material cavity, and the discharging hole is communicated with the material cavity; the ink adding assembly further comprises a connecting pipe, the connecting pipe is provided with a first end part and a second end part which are respectively arranged at two different ends in the length direction of the connecting pipe, the first end part is connected to the discharging piece, and the pipe cavity of the connecting pipe is mutually communicated with the material cavity.

3. Doctor apparatus according to claim 2, characterized in that: the second end is higher than the first end in the vertical direction, and a connector used for being connected with an external feeding device is arranged on the second end.

4. Doctor apparatus according to claim 2, characterized in that: the discharging piece comprises a discharging plate and a storage seat, the discharging plate is fixedly arranged on one side of the storage seat, a material cavity is formed between the discharging plate and the storage seat, and the discharging hole is formed in the discharging plate and penetrates through the discharging plate in the thickness direction of the discharging plate.

5. Doctor apparatus according to claim 4, characterized in that: the discharging plate is fixedly arranged on the ink return knife, a material injection port is formed in the top of the material storage seat, and the first end portion is connected to the material injection port.

6. Doctor apparatus according to claim 1, characterized in that: all the discharging holes are uniformly arranged at intervals in the length extending direction of the discharging piece, and the distance between the two outermost discharging holes in the length extending direction of the discharging piece is smaller than the length of the ink return knife.

7. Doctor apparatus according to claim 1, characterized in that: the bottom surface of the discharging piece is higher than the bottom surface of the ink returning knife in the vertical direction, and/or orthographic projections of all the discharging holes on the side surface, close to one side of the discharging piece, of the ink returning knife fall on the side surface, close to one side of the discharging piece, of the ink returning knife.

8. Doctor apparatus according to claim 1, characterized in that: at least part of the ink returning knife is positioned on a discharge path of the slurry flowing out through the discharge hole; or, the scraper device further comprises a guide plate arranged between the ink returning knife and the discharging piece, and at least part of the guide plate is positioned on the discharging path of the slurry flowing out through the discharging hole.

9. Doctor apparatus according to claim 8, characterized in that: the discharge hole is in contact with the ink returning knife, or the discharge hole is in contact with the guide plate, wherein the guide plate is fixedly arranged on the ink returning knife, and the lowest point of the guide plate is higher than the knife edge of the ink returning knife.

10. Doctor apparatus according to any of claims 1-9, characterized in that: the length extension direction of the scraper is parallel to the length extension direction of the ink returning knife, the scraper and the ink returning knife are arranged at intervals along a preset translation direction, the translation direction is perpendicular to the length direction of the ink returning knife, and the discharging piece is arranged between the scraper and the ink returning knife.

11. Doctor apparatus according to claim 10, characterized in that: the scraper device further comprises a mounting seat, and the scraper and the ink return knife are respectively arranged on the mounting seat in a lifting manner along the vertical direction.

12. Doctor apparatus according to claim 1, characterized in that: the ink adding assembly further comprises a connecting pipe, wherein the connecting pipe comprises a first connecting pipe and a plurality of second connecting pipes which are connected and communicated with the first connecting pipe, and the second connecting pipes are correspondingly connected with the discharging holes one by one;

or, the inking component further comprises a plurality of second connecting pipes, one ends of the second connecting pipes are connected with and communicated with an external feeding device, and the other ends of the second connecting pipes are connected with the discharging holes in a one-to-one correspondence manner.

13. Doctor apparatus according to claim 12, characterized in that: the second connecting pipe is provided with a flow valve; and/or, the pipe diameters of the plurality of second connecting pipes are different; and/or the apertures of the plurality of discharging holes are different.

14. A screen coating apparatus characterized in that: a doctor apparatus comprising a doctor apparatus according to any of claims 1 to 13.