Blind pipe brushing device

Abstract

The utility model relates to the technical field of photovoltaics and semiconductors, in particular to a blind pipe brushing device which comprises a material conveying pipe comprising an output end, and the output end is configured to output paint; the interior of the brush head is hollow to form a material storage cavity, the first end of the brush head is hinged to the output end of the material conveying pipe, the brush head is provided with a brushing face matched with the inner surface of the blind pipe to be brushed, and a plurality of discharging holes are formed in the brushing face of the brush head; the sliding piece is arranged on the conveying pipe in a sleeving manner; two ends of the connecting piece are respectively hinged with the sliding piece and the brush head; and the driving assembly is in transmission connection with the sliding part, and the driving assembly is configured to drive the sliding part to move in the axis direction of the material conveying pipe so that the brush head can rotate around the first end. And the uniformity of the coating can be ensured when the high-temperature-resistant coating is prepared on the cambered surface part of the blind pipe.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of photovoltaic and semiconductor technology, and in particular to a blind tube brush coating device. BACKGROUND

[0002] Quartz glass is applied in many fields due to its excellent performance, especially in the high-end field of the rapidly developing photovoltaic and semiconductor industries. Quartz tubes are often used as reaction cavities for film coating processes in tube furnaces, and quartz blind tubes are a special processing of quartz tubes, and the inner wall of the quartz blind tube needs to be coated with a high-temperature resistant coating for protection. In the related art, a high-temperature resistant coating is often prepared by spraying, but the general spraying process is only suitable for the inner side wall of the quartz tube, and it is difficult to control the uniformity of the arc surface of the blind tube. CONTENT OF THE UTILITY MODEL

[0003] Therefore, the embodiments of the present application provide a blind tube brush coating device which can ensure the uniformity of the high-temperature resistant coating when the high-temperature resistant coating is prepared on the arc surface of the blind tube.

[0004] According to the inventive concept of one aspect of the present application, a blind tube brush coating device is provided, which comprises a material conveying pipe, a brush head, a sliding member, a connecting member and a driving assembly. The material conveying pipe comprises an output end configured to output coating material. The brush head has a hollow interior forming a material storage cavity, a first end of the brush head is hingedly connected to the output end of the material conveying pipe, the brush head has a coating surface matched with the inner surface of the blind tube to be coated, and a plurality of material outlet holes are formed in the coating surface of the brush head. The sliding member is sleeved on the material conveying pipe. The connecting member is hingedly connected to the sliding member and the brush head at two ends. The driving assembly is in transmission connection with the sliding member, and is configured to drive the sliding member to move along the axis direction of the material conveying pipe, so that the brush head rotates around the first end.

[0005] According to some embodiments of the present application, the blind tube brush coating device further comprises a coating layer made of flexible material and having a plurality of holes, and the coating layer is arranged on the coating surface.

[0006] According to some embodiments of the present application, the plurality of material outlet holes are arranged in an array on the coating surface.

[0007] According to some embodiments of the present application, the brush head comprises a second end opposite to the first end, and the plurality of material outlet holes are arranged on the coating surface close to the region of the second end.

[0008] According to some embodiments of the present application, the blind tube brush coating device further comprises a coating material recovery groove arranged on the output end and adjacent to the first end, and the coating material recovery groove is configured to recover the coating material dripped from the coating layer.

[0009] According to some embodiments of the present application, a plurality of the discharge holes are arranged on the entire brushing surface, the brush head further comprises a one-way valve, the one-way valve is arranged on the discharge hole close to the first end in the storage cavity, wherein the one-way valve is configured to be closed in response to the positive pressure state in the storage cavity, and to be opened in response to the negative pressure state in the storage cavity.

[0010] According to some embodiments of the present application, the blind pipe brushing device further comprises a pressure pump connected with the material conveying pipe, the pressure pump is configured to pump the coating into the material conveying pipe or to suck the coating in the material conveying pipe back.

[0011] According to some embodiments of the present application, the diameter of the discharge hole increases with the distance from the first end; and / or the number of the discharge holes on the brushing surface increases with the distance from the first end.

[0012] According to some embodiments of the present application, the discharge hole is obliquely arranged on the brushing surface, and the axis of the discharge hole is oblique to the first end, wherein the discharge hole is configured to return the residual coating in the brushing layer to the storage cavity along the discharge hole under the action of gravity in response to the brush head being in the vertical state.

[0013] According to some embodiments of the present application, the driving assembly comprises an electric cylinder, a pneumatic cylinder or a hydraulic cylinder.

[0014] The blind pipe brushing device according to the embodiments of the present application can conveniently and quickly brush the inner arc surface of the blind pipe by hingedly connecting the brush head matched with the arc of the blind pipe with the front end of the material conveying pipe, and opening or retracting the brush head by cooperating with the driving assembly, the sliding member and the connecting member, thereby improving the uniformity of the arc surface brushing. BRIEF DESCRIPTION OF DRAWINGS

[0015] The above and other objects, features and advantages of the present application will become more apparent from the following detailed description thereof taken in conjunction with the accompanying drawings. The drawings provided herein are for illustrative purposes only and constitute part of the description of the present application. They serve to further explain certain aspects of the present application, but not to limit the present application. In the drawings, the same reference numerals generally refer to the same components or steps throughout the drawings.

[0016] Figure 1 Fig. 1 shows a front view of a blind pipe brushing device according to an embodiment of the present application.

[0017] Figure 2 Fig. 2 shows a perspective view of a blind pipe brushing device according to an embodiment of the present application.

[0018] Figure 3 Fig. 3 shows a perspective view of a blind pipe brushing device according to an embodiment of the present application. Figure 2A local structure of the middle A region is shown in an enlarged schematic view.

[0019] Figure 4 A half sectional view of a brush head part structure of a blind pipe brushing device is shown.

[0020] Figure 5 A partial structure schematic view of a brush head and a material conveying pipe of a blind pipe brushing device is shown.

[0021] Figure 6 A partial structure schematic view of a brush head and a material conveying pipe of a blind pipe brushing device is shown.

[0022] Figure 7 A partial structure schematic view of a brush head and a material conveying pipe of a blind pipe brushing device is shown.

[0023] Figure 8 A sectional view of a brush head close to one end of a material conveying pipe of a blind pipe brushing device is shown.

[0024] Figure 9 A one-way valve working state schematic view of a blind pipe brushing device in a case of conveying and withdrawing paint is shown.

[0025] Reference signs:

[0026] 1, material conveying pipe; 101, output end; 2, brush head; 201, material storage cavity; 202, material outlet hole; 3, sliding member; 4, connecting member; 5, driving assembly; 6, brushing layer; 7, recovery groove; 8, fixed support; 9, one-way valve. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the scope of protection of the present application.

[0028] Figure 1 A front view of a blind pipe brushing device is shown. Figure 2 A perspective view of a blind pipe brushing device is shown. Figure 3 A front view of a blind pipe brushing device is shown. Figure 2 A local structure of the middle A region is shown in an enlarged schematic view. Figure 4 A half sectional view of a brush head part structure of a blind pipe brushing device is shown.

[0029] According to the application concept of one aspect of the utility model, provide a kind of blind tube brush coating device, as shown in Figures 1 to 4 The blind tube brush coating device includes a material conveying pipe 1, a brush head 2, a sliding member 3, a connecting member 4 and a driving assembly 5. The material conveying pipe 1 includes an output end 101 configured to output paint. The brush head 2 is hollow inside and forms a storage cavity 201. The first end of the brush head 2 is hingedly connected to the output end 101 of the material conveying pipe 1. The brush head 2 has a brushing surface matching the inner surface of the blind tube to be brushed. A plurality of discharge holes 202 are formed on the outer brushing surface of the brush head 2. The sliding member 3 is sleeved on the material conveying pipe 1. The connecting member 4 is hingedly connected to the sliding member 3 and the brush head 2 at both ends. The driving assembly 5 is drivingly connected to the sliding member 3. The driving assembly 5 is configured to drive the sliding member 3 to move along the axis direction of the material conveying pipe 1, so that the brush head 2 rotates around the first end.

[0030] In the embodiment, by hingedly connecting the brush head 2 matching the inner arc surface of the blind tube to the front end of the material conveying pipe 1, and by opening or retracting the brush head 2 through the driving assembly 5, the sliding member 3 and the connecting member 4, the inner arc surface part of the blind tube can be conveniently and quickly brushed, and the uniformity of the arc surface brushing is improved.

[0031] In order to facilitate the description of the blind tube brush coating device provided by the embodiments of the present application, the following will be described in combination with Figure 1 The direction of the blind tube brush coating device is defined as shown in Figure 1 The end of the material conveying pipe 1 close to the brush head 2 is defined as the front end, and the end far away from the brush head 2 is defined as the rear end.

[0032] According to some optional embodiments of the utility model, the bottom of the blind tube to be brushed is an arc surface. Correspondingly, the brush head 2 is an arc-shaped brush head, and the brushing surface thereof is an arc surface. The curvature of the arc surface matches the arc surface of the bottom of the blind tube. Optionally, the side surface opposite to the brushing surface of the brush head 2 is a concave arc surface, and the connecting member 4 is hingedly connected to the concave arc surface. Specifically, a hinged support can be arranged on the concave arc surface, and the connecting member 4 is hingedly connected to the brush head 2 through the hinged support.

[0033] According to some embodiments of the utility model, the material conveying pipe 1 is a paint input device. During use, the front end of the material conveying pipe 1 is inserted into the blind tube. During this process, the brush head 2 and the material conveying pipe 1 maintain a substantially parallel state. That is, the sliding member 3 slides to the position farthest from the front end of the material conveying pipe 1. At this time, the connecting member 4 is attached to the material conveying pipe 1. During this process, the brush head 2 is in a retracted state.

[0034] After the feeding pipe 1 extends to the preset position inside the blind pipe, the driving assembly 5 is started, the output end 101 of the driving assembly 5 drives the sliding piece 3 to slide to the front end, the connecting piece 4 is driven to drive the brush head 2 to rotate around the front end of the feeding pipe 1, and the brush head 2 is gradually opened to the preset position, at this time, the brushing surface of the brush head 2 is attached to the arc surface of the blind pipe or is arranged at equal intervals. Specifically, the front end of the feeding pipe 1 can be directly extended to the bottom of the blind pipe in one step, and then the driving assembly 5 drives the brush head 2 to open to the arc surface of the blind pipe; or the front end of the feeding pipe 1 can be extended to a position close to the bottom of the blind pipe, for example, the front end of the device is 1-10 mm away from the bottom of the blind pipe, then the driving assembly 5 drives the brush head 2 to open to the preset position, at this time, the brushing surface of the brush head 2 is arranged at equal intervals from the arc surface inside the blind pipe, and finally the feeding pipe 1 is further extended until the brush head 2 is attached to the arc surface inside the blind pipe.

[0035] The coating is conveyed to the brush head 2 through the feeding pipe 1, the coating flows out through the discharge hole 202 arranged on the brushing surface, the feeding pipe 1 is rotated to drive the brush head 2 to rotate around the axis of the feeding pipe 1 for one circle, and the coating is uniformly brushed on the arc surface part of the blind pipe.

[0036] According to some embodiments of the present application, after the brush head 2 completes a brushing operation, the blind pipe brushing device can be retracted, that is, the blind pipe brushing device is pulled out of the inside space of the blind pipe, and after the coating is dried, the foregoing operation is repeated for secondary brushing or multiple times until the requirements for the coating thickness and uniformity are met.

[0037] According to some embodiments of the present application, after the brushing operation of the arc surface inside the blind pipe is completed, the coating is dried, and the spraying of the inner wall of the blind pipe can be performed, and this part of the content is not described in detail.

[0038] According to some embodiments of the present application, the blind pipe brushing device further comprises a brushing layer 6, the brushing layer 6 is made of a porous flexible material, and the brushing layer 6 is arranged on the brushing surface.

[0039] In the present embodiment, the coating conveyed to the brush head 2 flows into the inside of the brushing layer 6 through the discharge hole 202, the coating is uniformly distributed in the inside of the brushing layer 6 by virtue of the porous property of the brushing layer 6, so that the coating can be uniformly brushed on the arc surface inside the blind pipe.

[0040] According to some embodiments of the present application, the material of the brushing layer 6 can be porous polyurethane or sponge.

[0041] According to some embodiments of the present application, the plurality of discharge holes 202 are arranged in an array on the brushing surface.

[0042] In the embodiment, the plurality of discharge holes 202 are arranged in an m*n array on the coating surface to ensure that the paint can enter the coating layer 6 uniformly, and m and n are both integers greater than 1.

[0043] Figure 5 Fig. 2 shows a partial structure diagram of a brush head 2 and a material conveying pipe 1 of a blind pipe brush coating device according to an embodiment of the present application.

[0044] According to some embodiments of the present application, as shown in Fig. 2, the brush head 2 includes a second end opposite to the first end, and the plurality of discharge holes 202 are arranged on the coating surface in a region close to the second end. Figure 5

[0045] In the embodiment, by optimizing the opening position of the discharge hole 202, specifically, no discharge hole 202 is arranged on the coating surface close to one end of the material conveying pipe 1, which can avoid that the high-pressure paint is directly sprayed out of the discharge hole 202. Specifically, the discharge hole 202 is arranged in a non-bottom region of the coating surface, and the paint is converted from a horizontal transmission state to a vertical transmission state through the turning of the conveying pipe-brush head 2 in the conveying process, and then output through the discharge hole 202 after conveying for a certain height, which greatly reduces the risk of paint spraying out of the bottom discharge hole, and ensures that the paint enters the coating layer 6 more uniformly. It should be noted that, in the embodiment, the bottom refers to the end close to the material conveying pipe 1 when the brush head 2 is in an open state and the whole is in a vertical state.

[0046] Figure 6 Fig. 3 shows a partial structure diagram of a brush head 2 and a material conveying pipe 1 of a blind pipe brush coating device according to another embodiment of the present application.

[0047] According to some embodiments of the present application, as shown in Fig. 3, the blind pipe brush coating device further includes a paint recovery groove 7, which is arranged on the output end 101 (i.e., the front end) of the material conveying pipe 1, and is arranged adjacent to the first end. The paint recovery groove 7 is configured to recover the paint dripping from the coating layer 6. Figure 6 In the embodiment, during the coating process of the brush head 2, the coating layer 6 is extruded, and part of the paint may gather in the edge region of the coating layer 6. After the brush head 2 completes one circle of coating operation, the paint flows downward and gathers under the action of gravity. In order to prevent the gathered paint from dripping into the blind pipe and polluting the inner side wall of the blind pipe, the paint recovery groove 7 is arranged at the front end of the material conveying pipe 1 to recover the part of the gathered paint.

[0048] According to some embodiments of the present application, the blind pipe brush coating device further includes a pressure pump connected to the material conveying pipe 1, and the pressure pump is configured to pump the paint into the material conveying pipe 1 or suck the paint in the material conveying pipe 1 back.

[0049] According to some embodiments of the present application, the blind pipe brush coating device further includes a pressure pump connected to the material conveying pipe 1, and the pressure pump is configured to pump the paint into the material conveying pipe 1 or suck the paint in the material conveying pipe 1 back.​

[0050] In the present embodiment, the pressure pump is not only used to pump the paint into the storage cavity 201 of the brush head 2, but also reversely operates to suck back the paint in the delivery pipe 1, the storage cavity 201 and the paint on the coating layer 6 after each coating operation of the brush head 2. In this process, the storage cavity 201 is in a negative pressure state, and the residual paint in the coating layer 6 returns to the storage cavity 201 through the discharge hole 202 under the action of suction, and then is sucked back. When the brush head 2 performs the next coating operation, the pressure pump pumps the paint into the storage cavity 201 and the coating layer 6 again. Through the above operation, the amount of paint delivered into the coating layer 6 in each coating operation can be accurately controlled, and the film thickness of each coating operation can be controlled.

[0051] According to some embodiments of the present application, a flow meter is further arranged between (or on) the pressure pump and the delivery pipe 1 to count the amount of paint delivered / sucked back each time, so as to adjust and control the amount of output paint.

[0052] According to some embodiments of the present application, before the coating operation on the arc surface of the blind pipe, the pressure pump can be started to perform one or more times of pumping / sucking back operation in advance to perform wetting operation on the coating layer 6, so as to prevent the influence on the subsequent formal coating operation.

[0053] Figure 7 Fig. 2 shows a partial structure schematic view of the brush head 2 and the delivery pipe 1 of the blind pipe coating device provided by another embodiment of the present application, Figure 8 Fig. 3 shows a cross-sectional view of the brush head 2 close to one end of the delivery pipe 1 of the blind pipe coating device provided by an embodiment of the present application; Figure 9 Fig. 4 shows a working state schematic view of the one-way valve 9 of the blind pipe coating device in the case of delivering and sucking back paint.

[0054] According to some embodiments of the present application, as shown in Figures 7 to 9 Fig. 2, a plurality of discharge holes 202 are arranged on the entire coating surface, and the brush head 2 further comprises a one-way valve 9 arranged in the storage cavity 201 close to the discharge hole 202 of the first end. The one-way valve 9 is configured to be closed in response to the positive pressure state in the storage cavity 201, and to be opened in response to the negative pressure state in the storage cavity 201.

[0055] In the present embodiment, when the delivery pipe 1 inputs paint into the storage cavity 201, as shown in Figure 8 and Figure 9 (a) case, the arrow in the figure represents the flow direction of the paint, and the pressure in the storage cavity 201 is in a positive pressure state. Under the action of the pressure, the one-way valve 9 is closed, and the one-way valve 9 is attached to the discharge hole 202, so that the paint cannot be sprayed out (flow out) through the discharge hole 202; when the delivery pipe 1 sucks back the paint, as shown in Figure 8 and Figure 9As shown in case (b), the arrow in the figure represents the flow direction of the paint, the storage cavity 201 is in a negative pressure state, and under the action of the pressure, the one-way valve 9 is opened, and the discharge hole 202 is connected, at this time, the residual paint on the paint layer 6 outside the discharge hole 202 can be sucked back into the storage cavity 201 through the discharge hole 202, and then be sucked back, so as to prevent the residual paint on the paint layer 6 in the area from affecting the subsequent painting operation, and prevent the residual paint from gathering and dropping in the blind pipe.

[0056] According to some embodiments of the present application, the discharge hole 202 is obliquely arranged on the painting surface, and the axis of the discharge hole 202 is inclined to the first end, wherein the discharge hole 202 is configured to respond to the brush head 2 in the vertical state, and the residual paint in the paint layer 6 can flow back to the storage cavity 201 under the action of gravity along the discharge hole 202.

[0057] In the embodiment, by adjusting the opening direction of the discharge hole 202, by increasing the length of the liquid flow, increasing the resistance of the liquid in the flow process, improving the efficiency of the paint flowing back to the storage cavity 201, the residual paint in the paint layer 6 can be recycled more smoothly and completely, the working efficiency is improved, and the precision and controllability of the painting operation are improved.

[0058] According to some embodiments of the present application, the diameter of the discharge hole 202 increases with the distance from the first end; and / or the number of discharge holes 202 arranged on the painting surface increases with the distance from the first end.

[0059] In the embodiment, the areas swept (painted) by different height sections of the brush head 2 are not the same, the closer to the material conveying pipe 1, the smaller the swept (painted) area, and the amount of paint consumed is also less, based on this, the number, diameter, spacing and other parameters of the discharge hole 202 on the painting surface of the brush head 2 are adjusted, so that the paint flowing out of the paint layer 6 at different positions is not the same, but the thickness of the paint layer 6 formed in the swept (painted) area is substantially the same, so as to ensure more uniform painting.

[0060] According to some embodiments of the present application, the driving assembly 5 includes an electric cylinder, a pneumatic cylinder or a hydraulic cylinder.

[0061] According to some embodiments of the present application, optionally, the material conveying pipe 1 is formed by sequentially splicing a plurality of shorter material conveying short pipes, specifically, adjacent two sections are connected and fixed by a clamping sleeve, which can be flexibly adjusted according to the length of the pipe, and has stronger applicability.

[0062] In the embodiments of the present disclosure, if not specifically limited, the form of connection can be detachable connection through bolt nut, screw, buckle, magnetic attraction and the like. In some connections, if there is no special requirement for the form of detachable cooperation, it can be connected in a non-detachable manner through welding, bonding and the like.

[0063] The above describes the basic principles of the present application in combination with specific embodiments. However, it should be noted that the advantages, advantages, effects and the like mentioned in the present application are only examples and not limitations, and these advantages, advantages, effects and the like cannot be considered as necessary for each embodiment of the present application. In addition, the above specific details disclosed are only for the purpose of example and understanding, and are not limited to the above specific details. The above details do not limit the present application to the above specific details.

[0064] The block diagrams of the devices, apparatuses, equipment, systems involved in the present application are only illustrative examples and are not intended to require or imply the connection, arrangement, configuration shown in the block diagram. As those skilled in the art will recognize, these devices, apparatuses, equipment, systems can be connected, arranged, configured in any manner. Words such as "include", "contain", "have" and the like are open-ended words, which mean "including but not limited to", and can be used interchangeably. The words "or" and "and" used herein mean the word "and / or", and can be used interchangeably unless the context clearly indicates otherwise. The word "such as" used herein means the phrase "such as but not limited to", and can be used interchangeably.

[0065] It should also be noted that in the devices, equipment and methods of the present application, each component or each step can be decomposed and / or recombined. These decompositions and / or recombination should be considered as equivalent solutions of the present application.

[0066] The above description of the disclosed aspects is provided so that any person skilled in the art can make or use the present application. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of the present application. Therefore, the present application is not intended to be limited to the aspects shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

[0067] The above description has been given for the purpose of illustration and description. Furthermore, this description is not intended to limit the embodiments of the present application to the forms disclosed herein. Although a number of example aspects and embodiments have been discussed above, those skilled in the art will recognize certain modifications, alterations, changes, additions and subcombinations thereof.

Claims

1. A blind pipe brushing apparatus, characterized by, The utility model relates to a blind pipe brushing device, comprising: a feeding pipe comprising an output end configured to output paint; a brush head internally hollowed to form a paint storage cavity, a first end of the brush head being hingedly connected to the output end of the feeding pipe, the brush head having a brushing surface matching an inner surface of a blind pipe to be brushed, a plurality of paint outlet holes being formed in the brushing surface of the brush head; a sliding member sleeved on the feeding pipe; a connecting member having two ends hingedly connected to the sliding member and the brush head respectively; a driving assembly in transmission connection with the sliding member, the driving assembly being configured to drive the sliding member to move along an axial direction of the feeding pipe so as to rotate the brush head about the first end.

2. The blind tube brushing apparatus according to claim 1, wherein, Further comprising: a brushing layer made of porous flexible material, the brushing layer being applied to the brushing surface.

3. The blind tube brushing apparatus of claim 2, wherein, The plurality of paint outlet holes are arranged in an array on the brushing surface.

4. The blind tube brushing apparatus of claim 3, wherein, The brush head comprises a second end opposite to the first end, and the plurality of paint outlet holes are arranged on the brushing surface close to the second end.

5. The blind tube brushing apparatus of claim 4, wherein, The blind pipe brushing device further comprises a paint recovery groove arranged on the output end, the paint recovery groove being arranged adjacent to the first end, the paint recovery groove being configured to recover paint dripping from the brushing layer.

6. The blind tube brushing apparatus of claim 4, wherein, The plurality of paint outlet holes are arranged on the entire brushing surface, and the brush head further comprises a one-way valve arranged on the paint outlet hole close to the first end in the paint storage cavity, wherein the one-way valve is configured to be closed in response to a positive pressure state in the paint storage cavity and to be opened in response to a negative pressure state in the paint storage cavity.

7. The blind tube brushing apparatus according to any one of claims 1 to 6, characterized in that The blind pipe brushing device further comprises: a pressure pump connected to the feeding pipe, the pressure pump being configured to pump paint into the feeding pipe or to suck paint in the feeding pipe back.

8. A blind pipe brushing apparatus according to any one of claims 3 to 6, wherein The diameter of the paint outlet hole increases with the distance from the first end; and / or The number of the paint outlet holes on the brushing surface increases with the distance from the first end.

9. The blind tube brushing apparatus of claim 3, wherein, The paint outlet hole is obliquely formed in the brushing surface, and an axis of the paint outlet hole is obliquely directed to the first end, wherein the paint outlet hole is configured to allow paint remaining in the brushing layer to flow back to the paint storage cavity along the paint outlet hole under the action of gravity in response to the brush head being in a vertical state.

10. The blind tube brushing apparatus of claim 1, wherein, The driving assembly comprises an electric cylinder, a pneumatic cylinder or a hydraulic cylinder.

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