Diffusion powder uniform coating process and device for LED tube processing

Abstract

The application relates to the technical field of LED lamp tube processing, in particular to a diffusion powder uniform coating process and device for LED lamp tube processing, which comprises a conveying rack, symmetrical synchronous belts are arranged on the two sides in the conveying rack, a plurality of material supporting frames are equidistantly arranged on the outer wall of the synchronous belts along the length direction, a mounting frame is fixedly arranged on the top of the conveying rack, an elevating plate is fixedly arranged on the mounting frame through an electric push rod, coating units in staggered reverse motion are arranged on the two sides of the elevating plate, and an auxiliary unit for driving the rotation of the lamp tube through a supporting wheel is arranged at the bottom; the application realizes self-adaptive coaxial rolling clamping and follow-up synchronous spraying, avoids the uneven coating caused by eccentricity and sagging, realizes coating, self-checking and supplementary coating integrated control and double-follow-up-frame continuous collaborative operation, reduces the rework cost, breaks through the process interval limitation, matches rolling type uniform hot air drying treatment, avoids defects such as sagging and cracking, and comprehensively optimizes the coating effect.

Description

Technical Field

[0001] This invention relates to the field of LED tube processing technology, and in particular to a uniform coating process and apparatus for diffusion powder in LED tube processing. Background Technology

[0002] LED tubes are energy-saving tubular lighting devices that use light-emitting diodes (LEDs) as their core light-emitting element to replace traditional fluorescent tubes. They typically employ standardized tubular structures such as T5 and T8, are compatible with existing universal lamp holders, and integrate LED chips, driver modules, and heat dissipation components internally. To optimize light diffusion uniformity, avoid glare caused by direct light from the LED chips, and ensure lighting comfort, the inner wall of these tubes needs to be coated with a diffusion powder coating. This is currently the mainstream lighting product requiring internal wall coating processing in mass production.

[0003] In existing LED tube inner wall diffusion powder coating processes, vertical static spraying combined with gravity casting and residual material recovery is a widely used method. The specific operation process is as follows: the tube is fixed vertically, and diffusion powder is sprayed into the tube through a top nozzle. Gravity drives the powder to flow downwards along the tube wall, while residual material collected at the bottom of the tube is recovered. However, during the vertical flow, the powder is continuously pulled by gravity, easily causing sagging. Specifically, the powder in the upper area of ​​the tube fails to deposit sufficiently due to rapid downward flow, resulting in a thinner coating; while in the lower area, the powder continuously accumulates and stacks, resulting in a significantly thicker coating. Ultimately, this leads to a large variation in the coating thickness of the entire inner wall of the tube, severely affecting the uniform diffusion effect of the LED light.

[0004] To address the aforementioned technical deficiencies, a solution is proposed. First, adaptive coaxial rolling clamping and follow-up synchronous rotation spraying eliminate uneven coating caused by eccentricity and sagging. Second, integrated control of coating, self-inspection, and touch-up coating, along with continuous collaborative operation of dual follow-up frames, reduces rework costs and overcomes process interval limitations. Third, rolling uniform hot air drying avoids defects such as sagging and cracking, ensuring coating smoothness and stable optical performance, thus comprehensively optimizing the coating effect. Summary of the Invention

[0005] The purpose of this invention is to provide a uniform coating process and apparatus for diffusion powder in LED tube manufacturing, in order to solve the aforementioned technical defects.

[0006] The objective of this invention can be achieved through the following technical solution: a uniform coating device for diffusion powder in LED tube processing, comprising a conveyor frame, synchronous belts symmetrically arranged on both sides of the conveyor frame, and multiple material support frames equidistantly installed on the outer wall of the synchronous belts along their length direction, with rollers rotatably connected to both sides of each material support frame, a mounting frame fixedly installed on the top of the conveyor frame, and a lifting plate fixedly installed on the mounting frame via an electric push rod, coating units with staggered and opposite movements arranged on both sides of the lifting plate, and an auxiliary unit at the bottom that cooperates with the rollers to drive the tube to rotate.

[0007] Preferably, the top of the lifting plate is fixedly connected to a guide tube that is slidably connected to the mounting frame, the auxiliary unit includes a pressing machine frame, and the top of the pressing machine frame is fixedly connected to a guide rod that is slidably connected to the corresponding guide tube, and a limit block is fixedly connected to the guide rod, and a limit groove that is slidably connected to the limit block is opened on the guide tube.

[0008] Preferably, rotating rollers are symmetrically rotatably connected to both sides of the pressing machine frame, and the rotating rollers are rotatably connected to each other through a pressing belt. A pressing plate that is slidably connected to the pressing belt is fixedly connected inside the pressing machine frame. A motor that drives the corresponding rotating roller to rotate is installed on the pressing machine frame by bolts.

[0009] Preferably, the coating unit includes a follower frame, and two sets of slide rods are fixedly connected to the follower frame. A movable plate is slidably connected between the slide rods. Multiple coating tubes are fixedly installed at equal intervals on one side of the movable plate. A control valve is installed on the coating tube, and a nozzle and a laser thickness sensor are installed at the end. A lead screw threadedly connected to the movable plate is rotatably installed on the follower frame, and a servo motor that drives the lead screw to rotate is installed by bolts.

[0010] Preferably, two sets of slide rods are fixedly installed on both sides of the lifting plate and slidably connected to the corresponding follower frame. Sprockets are symmetrically rotatably connected to the top two sides of the lifting plate. The sprockets are connected to each other by chain drive. A motor that drives the corresponding sprocket to rotate is installed on the lifting plate by bolts.

[0011] Preferably, rotating rods are symmetrically rotatably connected to both sides inside the conveyor frame, and synchronous pulleys that mesh with the synchronous belt are fixedly installed on the rotating rods. A motor that drives the corresponding rotating rod to rotate is installed on the conveyor frame by bolts. A support plate that is slidably connected to the synchronous belt is fixedly connected inside the conveyor frame.

[0012] Preferably, a plurality of air outlet slots are provided on one side of the pallet, and a dispersing mesh plate is embedded in the air outlet slot. A flow divider is fixedly connected to the bottom of the pallet and below the air outlet slot, and the bottom of the flow divider is inclined. An air inlet pipe communicating with the flow divider is installed on the conveyor frame.

[0013] Preferably, a slide rod two is fixedly installed on the mounting bracket on the side away from the diverter, and a bidirectional screw is rotatably connected thereto. The bidirectional screw is symmetrically threaded with guide plates that are slidably connected to the slide rod two, and the bottoms of the two sets of guide plates are arranged in an octagonal shape.

[0014] The uniform coating process for diffusion powder used in LED tube manufacturing includes the following steps:

[0015] Step 1: Centering and horizontal movement of lamp tubes: The lamp tubes are placed on the rollers of the corresponding material racks on both sides. During the horizontal movement of multiple equally spaced lamp tubes driven by the synchronous belt, they are automatically centered by two sets of guide plates arranged in a figure-eight shape.

[0016] Step 2: Coating and Coaxial Clamping Positioning: The lamp tube is moved to the bottom of the pressing machine frame. The electric push rod pushes the lifting plate and lowers the pressing machine frame. After the pressing belt touches the lamp tube, the lifting plate continues to descend. With the sliding cooperation of the guide tube and the guide rod, the lamp tube is rolled and clamped by the gravity of the pressing machine frame and the material support frame until the coating tube and the lamp tube axis are aligned. Then, the electric push rod is stopped and the position is locked to ensure coaxial setting.

[0017] Step 3: Coating the inner wall with synchronous rotation: The pressure belt rotates, causing the lamp tubes to rotate synchronously. The tubes to be coated correspond one-to-one with the lamp tubes. One set of follower frames moves in the same direction and at the same speed as the lamp tubes, while another set of follower frames moves in the opposite direction and at the same speed. The moving plate drives the coating tube to be inserted into the lamp tube. The control valve is opened to inject the diffusion powder slurry. The powder slurry is sprayed out through the nozzle. Combined with the rotation of the lamp tubes, the inner wall is fully coated.

[0018] Step 4: Thickness detection and automatic recoating: After coating is completed, the laser thickness sensor detects the coating thickness and transmits data during the retraction of the coating tube. If the thickness is not up to standard, the controller controls the corresponding control valve to open and the lamp to rotate, so that the coating defect is aligned with the nozzle. The recoating is completed as the coating tube retracts. After the coating tube is completely withdrawn, another set of follower frames moves synchronously to the initial position to perform continuous and coordinated coating.

[0019] Step 5: Equal Thickness Drying and Shaping Treatment: The coated lamp tubes continue to rotate under the cooperation of the pressure belt and the support rollers to maintain the fluid state of the coating with equal thickness. The lamp tubes move to the top of the air outlet duct, and hot air enters the distribution hood through the air inlet pipe. It is then blown evenly onto the rolling lamp tubes through the dispersion mesh plate of the air outlet duct to complete the equal thickness drying of the inner wall coating.

[0020] The beneficial effects of this invention are as follows:

[0021] (1) The present invention drives the lifting plate to descend by an electric push rod. The sliding cooperation between the guide tube and the guide rod, combined with the gravity of the pressing machine frame and the support roller of the material support frame, forms a rolling clamp, which automatically adapts to lamp tubes of different diameters and accurately calibrates the coaxial position of the coating tube and the lamp tube, thus eliminating the problem of uneven coating thickness caused by eccentricity. At the same time, during the process of one set of follower frames moving in the same direction and at the same speed as the lamp tube, the pressing belt drives the lamp tube to rotate, so that the coating tube can achieve 360° no dead angle spraying on the inside of the lamp tube during the follower process, while avoiding the problem of local coating areas being too thin or too thick due to the drip phenomenon caused by the lamp tube being stationary after coating, thereby improving the coating uniformity of the inner wall of the LED lamp tube.

[0022] (2) This invention integrates a laser thickness sensor at the end of the coating tube to detect the coating thickness in real time during the process of the coating tube exiting the lamp tube. By controlling the control valve and the lamp tube rotation drive component in conjunction with the control system, the defective areas with insufficient thickness are accurately recoated, realizing integrated control of coating and detection, avoiding the rework cost and time loss of offline detection. At the same time, a design of two sets of staggered and reverse moving follower frames is adopted. After one set of follower frames completes the coating and recoating and exits, the other set of follower frames moves synchronously to the initial station to perform the connecting coating operation, eliminating the process interval limitation of a single coating unit and realizing continuous collaborative coating.

[0023] (3) The coated lamp tube of the present invention maintains a uniform rotation speed under the cooperation of the pressure belt and the support roller, so that the fluid slurry on the inner wall is always in a state of uniform thickness, and eliminates the defect of slurry dripping caused by gravity accumulation during static drying; at the same time, hot air is sent into the distribution hood through the air inlet pipe, and through multiple air outlet slots on the support plate and the embedded dispersion mesh plate, a uniformly diffused hot air field is formed, ensuring that the hot air is in full contact with the outer wall of the rolling lamp tube, realizing the uniformity of coating circumferential temperature and wind speed, and avoiding the problems of coating cracking, yellowing and diffusion performance degradation caused by local overheating. Attached Figure Description

[0024] The invention will now be further described with reference to the accompanying drawings;

[0025] Figure 1 This is a schematic diagram of the structure of the present invention;

[0026] Figure 2 This is a schematic diagram of the installation of the timing belt of the present invention;

[0027] Figure 3 This is a schematic diagram of the air outlet duct configuration of the present invention;

[0028] Figure 4 This is a schematic diagram of the installation of the material support frame of the present invention;

[0029] Figure 5 This is a schematic diagram showing the cooperation between the lifting plate and the coating unit of the present invention;

[0030] Figure 6 This is a schematic diagram showing the cooperation between the auxiliary unit and the coating unit of the present invention;

[0031] Figure 7 This is a schematic diagram showing the disassembly of the lifting plate and the pressing frame of the present invention;

[0032] Figure 8 This is a schematic diagram of the installation of the mobile board of the present invention.

[0033] Legend:

[0034] 1. Conveyor frame; 11. Synchronous belt; 12. Material support frame; 13. Support rollers; 14. Mounting frame; 15. Motor 3; 16. Support plate; 17. Air outlet duct; 18. Dispersion mesh plate; 19. Diverter hood; 110. Air inlet pipe; 111. Bidirectional screw; 112. Guide plate;

[0035] 2. Lifting plate; 21. Electric push rod; 22. Guide tube; 23. Limiting groove; 24. Chain; 25. Motor II;

[0036] 3. Pressing frame; 31. Guide rod; 32. Limit block; 33. Pressing belt; 34. Pressing plate; 35. Machine 1;

[0037] 4. Follower frame; 41. Moving plate; 42. Coating tube; 43. Spray nozzle; 44. Lead screw; 45. Servo motor. Detailed Implementation

[0038] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0039] Example 1: Please refer to Figures 1-8 As shown, the problem of dripping and significant thickness deviation of the coating on the inner wall of the entire lamp tube caused by the vertical static spraying method can be solved by the following solutions;

[0040] The diffusion powder uniform coating device for LED tube processing in this embodiment includes a conveyor frame 1. A synchronous belt 11 is symmetrically arranged on both sides inside the conveyor frame 1. Multiple material support frames 12 are equidistantly installed on the outer wall of the synchronous belt 11 along its length direction. Both sides of the material support frame 12 are rotatably connected to the support rollers 13. The synchronous belt 11 drives the multiple material support frames 12 to move. Combined with the two sets of support rollers 13 on the material support frame 12, it is used to realize the equidistant conveying of multiple tubes and avoid interference with the rotation of the tubes during the conveying process.

[0041] A mounting frame 14 is fixedly installed on the top of the conveyor frame 1, and a lifting plate 2 is fixedly installed on the mounting frame 14 via an electric push rod 21. Coating units with staggered and opposite movements are provided on both sides of the lifting plate 2, and an auxiliary unit that works with the support roller 13 to drive the lamp tube to rotate is provided at the bottom.

[0042] The top of the lifting plate 2 is fixedly connected to a guide tube 22 that is slidably connected to the mounting frame 14. The auxiliary unit includes a pressing frame 3, and the top of the pressing frame 3 is fixedly connected to a guide rod 31 that is slidably connected to the corresponding guide tube 22. Through the slidable connection between the guide rod 31 and the guide tube 22, the lifting plate 2 can drive the coating unit to descend while carrying the pressing frame 3 to descend synchronously.

[0043] The pressure frame 3, under its own weight, forms a rolling clamp with the material support frame 12 and the rollers 13, automatically adapting to the fixing of lamp tubes of different diameters. It also precisely controls the coaxiality of the coating tube 42 and the lamp tube, eliminating the problem of uneven coating thickness caused by eccentricity. Furthermore, a limit block 32 is fixedly connected to the guide rod 31, and a limit groove 23 is provided on the guide tube 22 that slides with the limit block 32. Through the limit block 32 and the limit groove 23, the lifting plate 2 is first lifted and then the pressure frame 3 is lifted, so that the first lamp tube can be smoothly delivered to the bottom of the pressure frame 3.

[0044] The two sides of the pressing frame 3 are symmetrically connected to rotating rollers, and the rotating rollers are rotatably connected to each other by a pressing belt 33. The pressing plate 34 is fixedly connected inside the pressing frame 3 and is slidably connected to the pressing belt 33. The pressing plate 34 limits the pressing belt 33 below it, indirectly causing the pressing belt 33 to exert force on multiple lamp tubes. The pressing frame 3 is bolted with a motor 35 that drives the corresponding rotating roller to rotate. The motor 35 drives the corresponding rotating roller to rotate, thereby driving the pressing belt 33 to cause multiple lamp tubes that have moved to the bottom to rotate synchronously while moving horizontally, so as to achieve uniform coating in the subsequent process.

[0045] The coating unit includes a follower frame 4, and two sets of slide rods are fixedly connected to the follower frame 4. A moving plate 41 is slidably connected between the slide rods. Multiple coating tubes 42 are fixedly installed at equal intervals on one side of the moving plate 41. A control valve is installed on the coating tube 42, and a nozzle 43 and a laser thickness sensor are installed at the end. The nozzle 43 is installed at the end of the coating tube 42. There is an installation gap between the laser thickness sensor and the nozzle 43, so that when the coating tube 42 retracts from the lamp tube, the laser thickness sensor can detect the thickness of the coated area.

[0046] The follower frame 4 is rotatably mounted with a lead screw 44 threadedly connected to the moving plate 41, and a servo motor 45 that drives the lead screw 44 to rotate is mounted by bolts. When the follower frame 4 moves in the same direction and at the same speed as the lamp tube, the servo motor 45 drives the lead screw 44 to rotate, and the lead screw 44 pushes the moving plate 41 to move, so that the coating tube 42 is inserted into the corresponding lamp tube.

[0047] During the insertion of the coating tube 42, the external feeding equipment is connected to multiple coating tubes 42. The control valves on multiple coating tubes 42 are opened synchronously to inject diffusion powder into the interior of multiple coating tubes 42. The diffusion powder is sprayed onto the inner wall of the lamp tube through the nozzle 43. Combined with the synchronous rotation of multiple lamp tubes, the inner wall of the lamp tube is fully coated. This avoids the problem of local coating areas being too thin or too thick due to dripping after the lamp tube is left to stand. This improves the coating uniformity of the inner wall of the LED lamp tube.

[0048] When the coating tube 42 is removed from the inside of the lamp tube, the coating thickness of the rotating lamp tube is detected by the laser thickness sensor on the coating tube 42, and the detected thickness data is transmitted to the external control system. The controller in the control system receives the thickness data. If the coating thickness is less than the preset thickness, the controller controls the control valve on the corresponding coating tube 42 to open, and controls the motor 35 to drive the pressure belt 33 to rotate, so that the coating defect on the inner wall of the lamp tube moves and is maintained in the area directly below the nozzle 43. Then, in conjunction with the retraction process of the coating tube 42, the nozzle 43 moves to the coating defect for automatic recoating.

[0049] Two sets of sliding rods are fixedly installed on both sides of the lifting plate 2 and slidably connected to the corresponding follower frame 4. Sprockets are symmetrically rotatably connected to the top two sides of the lifting plate 2. The sprockets are connected to each other by a chain 24. A motor 25 is installed on the lifting plate 2 by bolts to drive the corresponding sprocket to rotate. The motor 25 drives the corresponding sprocket to rotate forward and backward, causing the chain 24 to carry the two sets of follower frames 4 to move alternately in opposite directions. Thus, after one set of follower frames 4 completes the coating and recoating and exits, the other set of follower frames 4 moves synchronously to the initial station to perform the connecting coating operation, eliminating the process interval limitation of a single coating unit and realizing continuous collaborative coating.

[0050] The conveyor frame 1 has symmetrical rotating rods on both sides, and synchronous pulleys that mesh with the synchronous belt 11 are fixedly installed on the rotating rods. The conveyor frame 1 is bolted with a motor 3 15 that drives the corresponding rotating rod to rotate. The motor 3 15 drives the corresponding rotating rod to rotate, and the synchronous pulley on the rotating rod drives the synchronous belt 11 to rotate, thereby driving multiple placed lamp tubes to move horizontally. The conveyor frame 1 has a fixedly connected support plate 16 that is slidably connected to the synchronous belt 11. The support plate 16 is used to stably support the synchronous belt 11, thereby improving the horizontal conveying stability of the lamp tubes, ensuring the rolling clamping stability, and further eliminating the problem of uneven coating thickness caused by conveying sway.

[0051] A slide bar 2 is fixedly installed on the mounting bracket 14 on the side away from the diverter 19, and a bidirectional screw 111 is rotatably connected to it. A handwheel is installed at one end of the bidirectional screw 111 to assist the rotation of the bidirectional screw 111. Guide plates 112 that are slidably connected to the slide bar 2 are symmetrically threaded on the bidirectional screw 111. The bottoms of the two sets of guide plates 112 are arranged in an octagonal shape. During the horizontal movement of multiple placed lamp tubes, they first pass through the space between the two sets of guide plates 112. The octagonal distribution of the two sets of guide plates 112 helps to center the lamp tubes between the material support brackets 12. By rotating the bidirectional screw 111, the distance between the two sets of guide plates 112 can be adjusted, thereby achieving the centered conveying of lamp tubes of different lengths.

[0052] Example 2: Please refer to Figures 1-4 As shown, the problem of coating sagging still occurring during subsequent transport after uniform coating can be solved by the following solutions;

[0053] In this embodiment, synchronous belts 11 are symmetrically arranged on both sides of the conveyor frame 1, and multiple material support frames 12 are equidistantly installed on the outer wall of the synchronous belt 11 along its length direction. Both sides of the material support frame 12 are rotatably connected to the support rollers 13.

[0054] The two sides of the pressing frame 3 are symmetrically connected to rotating rollers, and the rotating rollers are rotatably connected to each other through the pressing belt 33. The pressing plate 34 is fixedly connected inside the pressing frame 3 and is slidably connected to the pressing belt 33. The motor 35 that drives the corresponding rotating roller to rotate is installed on the pressing frame 3 by bolts.

[0055] Multiple air outlet slots 17 are provided on one side of the pallet 16. The air outlet slots 17 are all located below the pressing frame 3. A dispersing mesh plate 18 is embedded inside the air outlet slot 17. A diversion hood 19 is fixedly connected to the bottom of the pallet 16 and below the air outlet slot 17. The bottom of the diversion hood 19 is inclined. An air inlet pipe 110 communicating with the diversion hood 19 is installed on the conveyor frame 1. The air inlet pipe 110 is installed on the side of the lowest point of the bottom of the diversion hood 19. When the air inlet pipe 110 blows hot air into the diversion hood 19, the inner cavity of the diversion hood 19 along the blowing direction is reduced, which makes the hot air blown out from each area of ​​the air outlet slot 17 at the same speed, ensuring the uniformity of the drying rate of the coating.

[0056] The coated lamp tube rotates continuously under the cooperation of the pressure belt 33 and the support roller 13, maintaining the uniform thickness of the fluid diffusion powder coating on the inner wall of the lamp tube. This prevents the powder from dripping due to gravity accumulation during static drying. The rolling lamp tube moves above multiple air outlet slots 17, and hot air is injected into the distribution hood 19 through the air inlet pipe 110. The hot air diffuses and contacts the rolling lamp tube through the dispersing mesh plate 18 in the multiple air outlet slots 17, ensuring that the hot air contacts the outer wall of the rolling lamp tube in all directions. This achieves uniform temperature and air velocity in the circumferential direction of the coating, and dries the diffusion powder coating on the inner wall of the lamp tube to a uniform thickness.

[0057] Example 3: Please refer to Figures 1-8 As shown, the present invention also proposes a uniform coating process for diffusion powder in LED tube manufacturing, comprising the following steps:

[0058] Step 1: Centering and horizontal movement of lamp tubes: The lamp tubes are placed on the corresponding support racks 12 on both sides, and the support rollers 13 on the support racks 12 provide rolling support for the lamp tubes. The motor 15 drives the corresponding rotating rod to rotate, and the synchronous wheel on the rotating rod drives the synchronous belt 11 to rotate, thereby driving the multiple placed lamp tubes to move horizontally. The lamp tubes first pass through the two sets of guide plates 112. The two sets of guide plates 112 are arranged in an eight-shaped pattern to make the lamp tubes centered between the support racks 12.

[0059] Step 2: Coating and Coaxial Clamping Positioning: After the centered lamp tube is moved to the bottom of the pressing frame 3, the electric push rod 21 pushes the lifting plate 2 and carries the pressing frame 3 to move down synchronously until the pressing belt 33 on the pressing frame 3 touches the lamp tube limit. Then the lifting plate 2 continues to descend, and the guide tube 22 and the guide rod 31 slide against each other. The lamp tube is rolled and clamped by the gravity of the pressing frame 3 combined with the material support frame 12 until the center line height of the coating tubes 42 on both sides of the lifting frame is equal to the center line height of the lamp tube. Then the electric push rod 21 is stopped, and the descent height of the lifting plate 2 is maintained at this moment to ensure the coaxial setting of the coating tubes 42 and lamp tubes of different diameters.

[0060] Step 3: Coating the inner wall of the rotating wall in a synchronous motion: Motor 1 35 drives the corresponding rotating roller to rotate, which in turn drives the pressure belt 33 to cause multiple lamps that have moved to the bottom to rotate synchronously. When the same number of lamps as the one on the guide plate 112 and the moving plate 41 move to the bottom of the pressure belt 33, and the multiple coating tubes 42 correspond one-to-one with the positions of the corresponding lamps, Motor 2 25 drives the corresponding sprocket to rotate. The sprocket drives the follower frame 4 to move in the same direction and at the same speed as the lamps through the chain 24. Another set of follower frames 4 moves in the opposite direction at the same speed.

[0061] As the follower frame 4 moves in the same direction and at the same speed as the lamp tube, the servo motor 45 drives the lead screw 44 to rotate. The lead screw 44 pushes the moving plate 41 to move closer to the lamp tube, so that the coating tube 42 is inserted into the corresponding lamp tube. During the insertion process, the external feeding equipment is connected to multiple coating tubes 42, and the control valves on multiple coating tubes 42 are opened synchronously to inject diffusion powder into the multiple coating tubes 42. The diffusion powder is sprayed onto the inner wall of the lamp tube through the nozzle 43. Combined with the synchronous rotation of multiple lamp tubes, the comprehensive coating treatment of the inner wall of the lamp tube is completed.

[0062] Step 4: Thickness Detection and Automatic Re-coating: After coating is completed, the control valve is closed, and the servo motor 45 drives the lead screw 44 to rotate in the opposite direction, moving the coating tube 42 out of the lamp tube. During the retraction process, the laser thickness sensor on the coating tube 42 first detects the coating thickness of the rotating lamp tube and transmits the detected thickness data to the external control system. The controller in the control system receives the thickness data. If the coating thickness is less than the preset thickness, the controller controls the control valve on the corresponding coating tube 42 to open and controls the motor 35 to drive the pressure belt 33 to rotate, so that the coating defect on the inner wall of the lamp tube moves and is maintained in the area directly below the nozzle 43. Then, combined with the retraction process of the coating tube 42, the nozzle 43 moves to the coating defect for automatic re-coating.

[0063] After the coating tube 42 is completely removed from the lamp tube, another set of synchronous follower frames 4 moves to the initial position of the coating tube 42. Then, the sprocket is driven to rotate in the opposite direction by motor 25. Combined with the insertion action of the coating tube 42 on the other set of follower frames 4, continuous and coordinated coating processing is carried out.

[0064] Step 5: Equal Thickness Drying and Shaping Treatment: The coated lamp tubes continue to rotate under the cooperation of the pressure belt 33 and the support roller 13, maintaining the uniform thickness of the fluid diffusion powder coating on the inner wall of the lamp tubes. The rolling lamp tubes move above the multiple air outlet slots 17, and hot air is injected into the distribution hood 19 through the air inlet pipe 110. The air diffuses through the dispersing mesh plate 18 in the multiple air outlet slots 17 to contact the rolling lamp tubes, drying the diffusion powder coating on the inner wall of the lamp tubes with equal thickness, and further completing the uniform coating.

[0065] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A device for uniformly coating diffusion powder for LED tube processing, comprising a conveyor frame (1), characterized in that, The conveyor frame (1) is symmetrically provided with synchronous belts (11) on both sides, and multiple material support frames (12) are equidistantly installed on the outer wall of the synchronous belt (11) along its length direction. Both sides of the material support frame (12) are rotatably connected with rollers (13). The top of the conveyor frame (1) is fixedly installed with a mounting frame (14), and a lifting plate (2) is fixedly installed on the mounting frame (14) by an electric push rod (21). The lifting plate (2) is provided with coating units that move in opposite directions on both sides, and an auxiliary unit is provided at the bottom to drive the lamp tube to rotate in coordination with the rollers (13).

2. The diffusion powder uniform coating device for LED tube processing according to claim 1, characterized in that, The top of the lifting plate (2) is fixedly connected to a guide tube (22) that is slidably connected to the mounting frame (14). The auxiliary unit includes a pressing machine frame (3), and the top of the pressing machine frame (3) is fixedly connected to a guide rod (31) that is slidably connected to the corresponding guide tube (22). A limit block (32) is fixedly connected to the guide rod (31), and a limit groove (23) that is slidably connected to the limit block (32) is provided on the guide tube (22).

3. The diffusion powder uniform coating device for LED tube processing according to claim 2, characterized in that, The two sides of the pressing machine frame (3) are symmetrically connected to rotating rollers, and the rotating rollers are rotatably connected to each other through the pressing belt (33). The pressing machine frame (3) is fixedly connected to the inside of the pressing machine frame (3) and is slidably connected to the pressing belt (33). A motor (35) that drives the corresponding rotating roller to rotate is installed on the pressing machine frame (3) by bolts.

4. The diffusion powder uniform coating device for LED tube processing according to claim 1, characterized in that, The coating unit includes a follower frame (4), and two sets of slide rods are fixedly connected on the follower frame (4). A moving plate (41) is slidably connected between the slide rods. Multiple coating tubes (42) are fixedly installed at equal intervals on one side of the moving plate (41). A control valve is installed on the coating tube (42), and a nozzle (43) and a laser thickness sensor are installed at the end. A lead screw (44) that is threadedly connected to the moving plate (41) is rotatably installed on the follower frame (4), and a servo motor (45) that drives the lead screw (44) to rotate is installed by bolts.

5. The diffusion powder uniform coating device for LED tube processing according to claim 4, characterized in that, Two sets of sliding rods are fixedly installed on both sides of the lifting plate (2) and are slidably connected to the corresponding follower frame (4). Sprockets are symmetrically rotated on both sides of the top of the lifting plate (2). The sprockets are connected to each other by a chain (24). A motor (25) that drives the corresponding sprocket to rotate is installed on the lifting plate (2) by bolts.

6. The diffusion powder uniform coating device for LED tube processing according to claim 1, characterized in that, The conveyor frame (1) has rotating rods symmetrically connected to both sides, and a synchronous wheel that meshes with the synchronous belt (11) is fixedly installed on the rotating rod. The conveyor frame (1) is equipped with a motor (15) that drives the corresponding rotating rod to rotate by bolts. The conveyor frame (1) has a support plate (16) that is slidably connected to the synchronous belt (11) inside.

7. The diffusion powder uniform coating device for LED tube processing according to claim 6, characterized in that, The pallet (16) has multiple air outlet slots (17) on one side, and a dispersing mesh plate (18) is embedded inside the air outlet slot (17). A diverter hood (19) is fixedly connected to the bottom of the pallet (16) and below the air outlet slot (17), and the bottom of the diverter hood (19) is inclined. An air inlet pipe (110) communicating with the diverter hood (19) is installed on the conveyor frame (1).

8. The device for uniformly coating diffusion powder for LED tube processing according to claim 1, characterized in that, A slide rod two is fixedly installed on the mounting bracket (14) on the side away from the diverter (19), and a bidirectional screw (111) is rotatably connected thereto. A guide plate (112) that is symmetrically threaded on the bidirectional screw (111) and slidably connected to the slide rod two is provided. The bottoms of the two sets of guide plates (112) are arranged in an octagonal shape.

9. A uniform coating process for diffusion powder in LED tube manufacturing, comprising the uniform coating apparatus for diffusion powder in LED tube manufacturing as described in any one of claims 1-8, characterized in that, Includes the following steps: Step 1: Centering and horizontal movement of lamp tubes: The lamp tubes are placed on the rollers (13) of the corresponding material racks (12) on both sides. During the horizontal movement of multiple equally spaced lamp tubes driven by the synchronous belt (11), they are automatically centered by two sets of guide plates (112) arranged in a figure-eight shape. Step 2: Coating and Coaxial Clamping Positioning: The lamp tube is moved to the bottom of the pressing machine frame (3). The electric push rod (21) pushes the lifting plate (2) and carries the pressing machine frame (3) down. After the pressing belt (33) touches the lamp tube, the lifting plate (2) continues to descend. With the sliding cooperation of the guide tube (22) and the guide rod (31), the lamp tube is rolled and clamped by the gravity of the pressing machine frame (3) and the material support frame (12) until the coating tube (42) is aligned with the center line of the lamp tube. Then the electric push rod (21) is stopped and the position is locked to ensure coaxial setting. Step 3: Coating the inner wall by synchronous rotation: The pressure belt (33) rotates and drives the lamp tube to rotate synchronously. The tube to be coated (42) corresponds to the lamp tube. One set of follower frames (4) moves in the same direction and at the same speed as the lamp tube. Another set of follower frames (4) moves in the opposite direction and at the same speed. The moving plate (41) drives the coating tube (42) to be inserted into the lamp tube. The control valve is opened to inject the diffusion powder slurry. The powder slurry is sprayed out through the nozzle (43). Combined with the rotation of the lamp tube, the inner wall is fully coated. Step 4: Thickness detection and automatic recoating: After coating is completed, the laser thickness sensor detects the coating thickness and transmits data during the retraction of the coating tube (42). If the thickness is not up to standard, the controller controls the corresponding control valve to open and the lamp to rotate, so that the coating defect is aligned with the nozzle (43). The recoating is completed as the coating tube (42) retracts. After the coating tube (42) is completely withdrawn, another set of follower frames (4) moves synchronously to the initial position to perform continuous and coordinated coating. Step 5: Equal thickness drying and shaping treatment: The coated lamp tubes continue to rotate under the cooperation of the pressure belt (33) and the support roller (13) to maintain the fluid state of the coating with equal thickness. The lamp tubes move to the top of the air outlet groove (17), and hot air enters the distribution hood (19) through the air inlet pipe (110). It is evenly blown onto the rolling lamp tubes through the dispersion mesh plate (18) of the air outlet groove (17) to complete the equal thickness drying of the inner wall coating.

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