A high-efficiency stable continuous electrostatic powder spraying device and a control method thereof

Abstract

The application is suitable for the technical field of electrostatic spraying equipment, and provides a high-efficiency stable continuous electrostatic powder spraying equipment, which comprises a main frame body, a base material conveying mechanism installed on the main frame body and used for conveying base materials needing to be sprayed, an electrostatic spraying mechanism arranged on the base material conveying mechanism and used for spraying the base materials on the base material conveying mechanism, a powder conveying mechanism connected with the electrostatic spraying mechanism, and a control module used for detecting parameters in the electrostatic spraying mechanism, so that the electrostatic spraying mechanism satisfies controllability and universality of base material spraying by controlling the size of the parameters. Thus, the application improves the feeding and conveying structure of the powder conveying system, adds a feeding pretreatment assembly, ensures uniform powder particle size and good fluidity, and integrates an intelligent monitoring module and a control method based on deep reinforcement learning, so as to realize real-time collection, analysis, optimization and feedback of spraying parameters.

Description

Technical Field

[0001] This invention relates to the field of electrostatic spraying equipment technology, and in particular to a high-efficiency, stable, and continuous electrostatic powder spraying equipment and its control method. Background Technology

[0002] Electrostatic powder coating technology, due to its environmental friendliness, excellent coating performance, and high resource utilization, has been widely used in substrate surface treatment across various industries, especially in the production of color-coated steel sheets, gradually replacing traditional solvent-based color coating processes to address the environmental problem of VOC emissions during solvent-based coating. However, there are still many technical bottlenecks in domestic electrostatic powder coating equipment and production processes, hindering its efficient, continuous, and intelligent development. These bottlenecks are manifested in the following aspects: First, the problem of uneven electrostatic field distribution is prominent. Traditional electrostatic powder coating equipment mostly adopts a single-electrode or simple multi-electrode structure. The unreasonable electrode layout leads to an uneven distribution of electrostatic field strength. The electric field strength is too high near the electrode area and insufficient in the area far from the electrode area. This causes uneven force on powder particles during electrostatic adsorption, ultimately resulting in uneven coating thickness on the substrate surface, and defects such as local missed spraying and accumulation. This seriously affects product quality and cannot meet the requirements of high-end coating for coating uniformity.

[0003] Secondly, traditional conveying systems cannot dynamically adjust the conveying volume according to the spraying requirements, which can easily lead to powder waste or insufficient spraying volume.

[0004] Third, existing electrostatic powder coating equipment mostly adopts manual operation or simple semi-automatic control methods, which cannot collect key parameters in the coating process in real time (such as electrostatic field strength, powder delivery, coating distance, substrate running speed, etc.); it lacks advanced control methods, especially model-based adaptive control strategies, and cannot achieve real-time optimization under multi-parameter coupling conditions. When parameter deviations occur, manual intervention is required, resulting in a delayed response. This not only increases the labor intensity of operators but also easily leads to product quality fluctuations, making it impossible to achieve efficient, continuous, and stable operation of the equipment.

[0005] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Summary of the Invention

[0006] To address the aforementioned shortcomings, the present invention aims to provide a highly efficient, stable, and continuous electrostatic powder coating equipment and its control method. This equipment improves the feeding and conveying structure of the powder transport system and adds pre-treatment components (screening, crushing, and drying) to ensure uniform powder particle size and good flowability. It also integrates an intelligent monitoring module and a control method based on deep reinforcement learning to achieve real-time acquisition, analysis, optimization, and feedback of coating parameters. Parameter adjustments can be completed without manual intervention, reducing the labor intensity of operators.

[0007] To achieve the above objectives, the present invention provides a high-efficiency, stable, continuous electrostatic powder coating device, comprising: Main frame; A substrate conveying mechanism, which is installed on the main frame, conveys the substrate to be sprayed; An electrostatic spraying mechanism is disposed on the substrate conveying mechanism and is used to spray the substrate on the substrate conveying mechanism. A powder conveying mechanism is connected to the electrostatic spraying mechanism and is used to supply powder to the electrostatic spraying mechanism. The powder conveying mechanism includes a powder storage bin and a feeding pretreatment component disposed at the bottom of the powder storage bin. The feeding pretreatment component screens, crushes and dries the powder material in order to ensure stable conveying of the powder material. The control module detects the parameters inside the electrostatic spraying mechanism and controls the magnitude of the parameters to ensure that the electrostatic spraying mechanism meets the requirements of controllability and versatility in substrate spraying.

[0008] In one embodiment, the substrate conveying mechanism includes a feed roller group and a discharge roller group, which are rotatably connected to the main frame. The substrate is wound around the feed roller group and the discharge roller group for conveying. A drive motor is provided on the feed roller group, which drives the feed roller group and the discharge roller to rotate. The substrate passes through the electrostatic spraying mechanism.

[0009] In one embodiment, the electrostatic spraying mechanism includes a spray gun assembly, an electrostatic generator, and an electrostatic field optimization component; wherein, the spray gun assembly is evenly arranged along the substrate conveying direction, and each spray gun corresponds to an independent adjustment unit, which can individually adjust the spraying angle, spraying distance, and spraying amount.

[0010] In one embodiment, the powder conveying mechanism includes: Powder storage bin; A pre-treatment feeding assembly, located at the bottom of the powder storage bin, is used to screen, crush, and dry the powder material. The conveying pipeline is used to connect the spray gun assembly and the feed pretreatment component for conveying powder materials. Each spray gun has a branch pipeline at its feed inlet. The conveying pipeline also includes a main pipeline, and the branch pipelines are connected to the main pipeline. A flow regulating valve is installed on each of the branch pipes to individually control the flow rate of the powder.

[0011] In one embodiment, the feed pretreatment assembly includes: The main housing has a filter element for filtering powdered materials inside. The main housing has a sieve material channel outside the filter element. The sieve material enters the sieve material channel from the top of the filter element. The top of the sieve material channel has a guide part that guides the airflow inside the sieve material channel to the filter element. The crushing component is rotatably connected to the inside of the screen material channel to crush the screen material entering the screen material channel; The drying element is connected to the bottom of the screen material channel, supplies high-pressure drying gas to the inside of the screen material channel, and blows the crushed screen material back into the top of the filter element.

[0012] In one embodiment, a gas channel is provided at the bottom of the oversize material channel, and a plurality of evenly arranged air inlets are provided at the top of the gas channel. The crushing component is disposed at the top of the air inlets. The crushing component includes an inner ring and an outer ring that are in close contact with the inner and outer walls of the oversize material channel. Crushing blades are provided between the inner and outer rings. The crushing blades are spirally inclined in the circumferential direction with an inclination angle of 30° to 60°, so that when the high-pressure gas ejected from the air inlets acts on the crushing blades, it generates a rotational torque to drive the crushing component to rotate and guides the crushed powder material upward. The crushing component can be driven by airflow reaction force or by a motor.

[0013] In one embodiment, the filter element includes an upper filter screen and a lower filter screen that are fixed to each other and installed vertically. The top of the upper filter screen and the lower filter screen are respectively provided with an upper guide plate and a lower guide plate. A rotary motor for driving the filter element to rotate is fixedly installed on the inner shell. The diameter of the filter element is larger than the bottom diameter of the conical opening and smaller than the maximum diameter of the material channel on the screen.

[0014] The present invention also provides a control method, comprising the following steps: Step 1: Equipment initialization and parameter setting. Initialize the control module and set the initial spraying parameters, including electrostatic field strength, powder conveying flow rate, spraying distance, substrate conveying speed, drying temperature, etc. The control module sends the initial parameters to each actuator to complete the equipment initialization. Step 2: Continuous conveying and pretreatment of substrate. Place the substrate to be sprayed on the substrate conveying mechanism, start the drive motor to drive the conveying roller group, and position and guide the substrate to ensure stable and accurate conveying of the substrate. Step 3: Powder pretreatment and stable conveying. The powder in the powder storage bin enters the feeding pretreatment component, where the powder material is screened, crushed and dried. Step 4: Electrostatic spraying and dynamic optimization of the electrostatic field. The electrostatic generator is started, and the electric field adjustment module adjusts the power supply parameters of each arc electrode according to the initial parameters to form a uniformly distributed electrostatic field. The spray gun assembly is started, and the powder is atomized and sprayed out. The powder particles are uniformly adsorbed on the surface of the substrate under the action of the electrostatic field. At the same time, the electrostatic field strength sensor collects the electrostatic field strength distribution data in real time and transmits it to the control module. The control module analyzes the data through control methods. If uneven electrostatic field distribution is detected, the electric field adjustment module is automatically controlled to adjust the power supply parameters of each arc electrode to dynamically optimize the electrostatic field distribution. Step 5: Real-time monitoring and automatic parameter optimization of the spraying process. The sensors of the control module collect key parameters in real time during the spraying process. At the same time, the collected data is processed by noise reduction and filtering, and transmitted to the control module in real time through the data transmission unit. The control module uses a control method based on deep reinforcement learning to analyze the parameters in real time, compare them with preset parameter thresholds, and determine the current spraying status. Step 6: Spraying Completion and Post-processing. After the substrate is sprayed, it is transported by the substrate conveying mechanism to the curing area for curing. After curing, it is transported to the discharge area to complete the entire spraying process. At the same time, the control module records the various parameter data and product quality data of this spraying, updates the parameter database, and provides a reference for subsequent spraying. If problems such as pipe blockage or electrode failure are detected during equipment operation, the control module will issue an alarm signal in a timely manner and stop the operation of the relevant mechanisms.

[0015] In one embodiment, in step 5, if a powder flow rate deviation is detected, the flow rate regulating valve and conveying pressure of the powder conveying mechanism are automatically adjusted to ensure stable powder supply and avoid blockage; if a spraying distance deviation is detected, the position of the spray gun is automatically adjusted to ensure that the spraying distance meets the set requirements; if a substrate speed deviation is detected, the speed of the variable frequency motor of the substrate conveying mechanism is automatically adjusted to achieve precise matching between the spraying rhythm and the conveying speed; if a coating thickness deviation is detected, the parameters of the relevant actuators are comprehensively adjusted in combination with parameters such as electrostatic field strength and powder flow rate to ensure that the coating thickness meets the standard; at the same time, the control method continuously learns from real-time data and historical data to optimize control parameters and improve spraying quality and production efficiency.

[0016] In one embodiment, the specific implementation of the electrostatic field dynamic optimization in step 4 is as follows: The electrostatic field optimization component adopts a ring-shaped multi-electrode structure, with eight arc-shaped electrodes evenly arranged circumferentially along the spraying area. Studies show that when using a needle-ring combined electrode structure, the median diameter and cross-sectional diameter of the ring electrode are closely related to the deposited film thickness and coating transfer rate. When the median diameter of the ring electrode is 50 mm and the cross-sectional diameter is 6 mm, the resulting electric field not only helps improve the atomization effect of the coating and make the film thickness distribution more uniform, but also helps to control the movement direction of charged particles in the electrostatic field, increasing the coating transfer rate by 5.04 percentage points compared to a needle-shaped single electrode.

[0017] Based on the above research results, this invention further configures each arc-shaped electrode to be independently powered, and each electrode is equipped with an independent voltage adjustment module and current detection module. Electrostatic field strength sensors are evenly arranged on both sides of the spraying area along the substrate conveying direction, with no fewer than six sensors, to collect real-time electric field strength distribution data at various points in space. When the control module detects that the electric field strength deviation in a certain area exceeds a set threshold (e.g., ±1kV / m), it automatically adjusts the power supply voltage (adjustment range 30~120kV, step size 0.5kV) and current parameters of the corresponding arc-shaped electrode, dynamically optimizing the electrostatic field distribution to ensure uniform electric field strength in all areas of the substrate surface.

[0018] The technical effects of this invention are as follows: This invention improves the feeding and conveying structure of the powder conveying system and adds a feeding pretreatment component to screen, crush, and dry the powder material, ensuring uniform powder particle size and good flowability. This effectively solves the conveying blockage problem caused by powder agglomeration and uneven particle size in traditional equipment.

[0019] This invention achieves dynamic optimization and adjustment of the electrostatic field through a ring-shaped multi-electrode structure combined with real-time electrostatic field strength sensor feedback, effectively solving the quality defects such as local leakage and accumulation caused by uneven electric field distribution in traditional equipment.

[0020] 3. This invention integrates a control module with a deep reinforcement learning-based control method to achieve real-time acquisition, analysis, optimization, and feedback of spraying parameters. Parameter adjustment can be completed without manual intervention, reducing the labor intensity of operators. The self-learning function of the control method can continuously optimize parameters based on historical data to adapt to different substrates and different spraying requirements. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the overall three-dimensional structure of the spraying equipment of the present invention; Figure 2 This is a schematic cross-sectional view of the powder pretreatment component of the present invention; Figure 3 This is a three-dimensional structural diagram of the powder pretreatment component of the present invention; Figure 4This is a cross-sectional three-dimensional structural diagram of the powder pretreatment component of the present invention; Figure 5 This is a schematic diagram of the three-dimensional structure of a crushing component according to an embodiment of the present invention; Figure 6 This is a schematic diagram of the three-dimensional structure of the crushing component according to another embodiment of the present invention; Figure 7 This is a flowchart of the control method of the present invention; In the diagram, 1-feed roller assembly, 2-guide roller, 3-substrate, 4-electrostatic spraying mechanism, 5-discharge roller assembly, 6-sub-pipeline, 7-flow regulating valve, 8-main housing, 81-conical inlet, 82-outer housing, 83-guide section, 84-screen material channel, 85-inner housing, 86-main pipeline, 9-crushing component, 10-upper filter screen, 101-upper guide plate, 11-lower filter screen, 111-lower guide plate, 12-air blowing port, 121-crushing blade, 122-inner and outer rings, 123-gear, 13-limiting plate, 14-gas channel, 15-rotating motor. Detailed Implementation

[0022] 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 a part of the embodiments of the present invention, and not all of the 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.

[0023] It should be noted that if the embodiments of the present invention involve directional indications (such as up, down, left, right, front, back, etc.), the directional indications are only used to explain the relative positional relationship and movement of the components in a specific posture. If the specific posture changes, the directional indications will also change accordingly.

[0024] Furthermore, if the embodiments of this invention involve descriptions such as "first" or "second," these descriptions are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the use of "and / or" or "and / or" throughout the text includes three parallel solutions. For example, "A and / or B" includes solution A, solution B, or a solution where both A and B are satisfied simultaneously. Furthermore, the technical solutions of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0025] See Figure 1 and Figure 2 This invention provides a high-efficiency, stable, continuous electrostatic powder coating equipment, comprising: The main frame is used to support the entire production line of the spraying equipment and ensure the spraying effect of substrate 3; The substrate conveying mechanism is installed on the main frame to convey the substrate 3 that needs to be sprayed, ensuring the conveying of the substrate 3 and achieving the normal spraying and conveying effect of the substrate 3. The electrostatic spraying mechanism 4 is installed on the substrate conveying mechanism and is used to spray the substrate 3 on the substrate conveying mechanism. During spraying, the substrate 3 can be conveyed, thereby effectively achieving the conveying effect of the substrate 3. The powder conveying mechanism is connected to the electrostatic spraying mechanism 4 and is used to supply powder to the electrostatic spraying mechanism 4. The powder conveying mechanism screens, dries and crushes the powder material to ensure stable conveying of the powder material, ensures smooth conveying of the powder material and prevents the powder material from getting blocked. The control module detects the parameters inside the electrostatic spraying mechanism 4 and controls the magnitude of the parameters to ensure that the electrostatic spraying mechanism 4 meets the controllability and versatility of the substrate 3 spraying, thereby optimizing the spraying effect and adapting to the spraying requirements of different substrates 3.

[0026] Specifically, in order to achieve the normal conveying effect of the substrate 3, the substrate conveying mechanism includes a feeding roller group 1 and a discharging roller group 5. The feeding roller group 1 and the discharging roller group 5 are rotatably connected to the main frame. The substrate 3 is wrapped around the feeding roller group 1 and the discharging roller group 5 for conveying. The feeding roller group 1 and the discharging roller group 5 cooperate with each other to form a normal conveying effect of the substrate 3. At the same time, a guide roller 2 is also provided on the main frame to guide the substrate 3 during the conveying process and prevent the substrate 3 from bending under the action of gravity, which would affect the spraying effect of the substrate 3. Meanwhile, a drive motor is provided on the feeding roller group 1 to drive the feeding roller group 1 and the discharging roller to rotate. The substrate 3 passes through the electrostatic spraying mechanism 4, thereby ensuring that when the substrate 3 passes through the inside of the electrostatic spraying mechanism 4, the electrostatic spraying mechanism 4 can effectively spray the substrate 3 inside.

[0027] In one embodiment, in order to better spray the substrate 3, the electrostatic spraying mechanism 4 includes a spray gun assembly, an electrostatic generator, and an electrostatic field optimization component; wherein, the spray gun assembly is evenly arranged along the conveying direction of the substrate 3, thereby achieving uniform and stable spraying of the substrate 3, and each spray gun corresponds to an independent adjustment unit, which can individually adjust the spraying angle, spraying distance, and spraying amount (existing technology, not described in detail), which facilitates subsequent control of the state of the spray gun, thereby controlling the adjustment of the spraying state of the substrate 3.

[0028] In another embodiment, to ensure proper delivery of the sprayed powder, the powder conveying mechanism includes: The powder storage bin is used to store powder, facilitating a continuous supply of powder materials to the feed pretreatment unit. The feeding pretreatment component, located at the bottom of the distribution and storage bin, is used to screen, crush, and dry powder materials, thereby ensuring the state of the powder materials during conveying and enabling smooth conveying of the powder materials. delivery pipeline, combined Figure 2 , Figure 3 and Figure 4 It is used to connect the spray gun assembly and the feed pretreatment component for conveying powder materials. Each spray gun has a branch pipe 6 at its feed port. The conveying pipe also includes a main pipe 86. The branch pipe 6 is connected to the main pipe 86, which facilitates the supply of powder materials in the subsequent spray gun assembly and ensures effective spraying of the internal substrate 3 by the spray gun. The flow regulating valve 7 is installed on the branch pipe 6. Each branch pipe 6 is equipped with a flow regulating valve 7 to control the flow rate of the powder individually, thereby controlling the supply of powder material and controlling the spraying effect.

[0029] In order to control the state of the powder material, the feed pretreatment component includes: The main housing 8 has a filter element inside for filtering powder materials. The main housing 8 has a screen material channel 84 outside the filter element. The screen material enters the screen material channel 84 from the top of the filter element. The top of the screen material channel 84 has a guide part 83. The guide part 83 guides the airflow inside the screen material channel 84 to the filter element. The guide part 83 can be an arc-shaped structure to ensure that the airflow and the powder blown synchronously with the airflow can be guided to the top of the filter element. On the one hand, it can ensure further screening of the powder material, and on the other hand, it can effectively ensure that the drying gas is guided to the top of the filter element to ensure further drying of the powder material. The crushing component 9 is rotatably connected to the inside of the screen material channel 84 to crush the screen material entering the screen material channel 84, thereby ensuring that the powder particles entering the screen material channel 84 are crushed, and at the same time ensuring that the crushed powder is blown onto the filter element at the top. The drying element is connected to the bottom of the screen material channel 84. It supplies high-pressure drying gas to the inside of the screen material channel 84 and blows the crushed screen material back into the top of the filter element, ensuring that the powder is conveyed to the top of the filter element again, thereby effectively realizing the recycling and screening of powder materials.

[0030] Specifically, in combination Figure 5 and Figure 6 To ensure normal ventilation and blowing effect, a gas channel 14 is provided at the bottom of the screen material channel 84, and a limiting plate 13 is provided at the top of the gas channel 14. Several evenly arranged air blowing ports 12 are provided on the limiting plate 13 at the top of the gas channel 14. The crushing component 9 is provided at the top of the air blowing port 12. The crushing component 9 includes an inner ring and an outer ring 122 that are closely attached to the inner and outer walls of the screen material channel 84. A crushing blade 121 is provided between the inner ring and the outer ring 122. The crushing component 9 rotates inside the screen material channel 84 under the action of external force, so as to effectively blow and transport the powder. Only when the crushed powder is blown can the powder blowing effect be achieved.

[0031] In another embodiment, in order to achieve better filtration of powder and convey the oversize material to the outer oversize material channel 84, the filter element includes an upper filter screen 10 and a lower filter screen 11 that are fixed to each other and installed vertically. The top of the upper filter screen 10 and the lower filter screen 11 are respectively provided with an upper guide plate 101 and a lower guide plate 111. A rotary motor 15 for driving the filter element to rotate is fixedly installed on the inner shell 85. The diameter of the filter element is larger than the bottom diameter of the conical opening 81 and smaller than the maximum diameter of the oversize material channel 84. This ensures that when the filter element rotates, the oversize material is directly conveyed into the oversize material channel 84 through the action of the guide plate, and the crushing, drying and circulation conveying effects are completed inside the oversize material channel 84.

[0032] Specifically, in order to better drive the crusher 9 to rotate inside the screen material channel 84, on the one hand, airflow can be used to react on the crushing blades 121, and the crusher 9 can be driven to rotate by the reaction force. On the other hand, a gear 123 can be set on the outer ring of the crusher 9, and the crusher 9 can be driven to rotate by a motor through a drive hole opened in the outer shell 82. This can effectively crush the powder material while ensuring the drying effect of the drying gas on the material.

[0033] In another embodiment, the electrostatic field optimization component adopts a ring-shaped multi-electrode structure, with eight arc-shaped electrodes evenly arranged circumferentially along the spraying area. Each arc-shaped electrode is independently powered and equipped with an independent voltage regulation module and current detection module. Electrostatic field strength sensors are evenly arranged on both sides of the spraying area along the substrate conveying direction, with no fewer than six sensors, to collect real-time electric field strength distribution data at various points in space. When the control module detects that the electric field strength deviation in a certain area exceeds a set threshold (e.g., ±1kV / m), it automatically adjusts the power supply voltage (adjustment range 30~120kV, step size 0.5kV) and current parameters of the corresponding arc-shaped electrode to dynamically optimize the electrostatic field distribution.

[0034] This embodiment provides a control method for a high-efficiency and stable continuous electrostatic powder coating equipment, combined with... Figure 7 This includes the following steps: Step 1: Device Initialization and Parameter Setting Upon starting the equipment, the control module performs an initial self-test, checking whether the substrate conveying mechanism, electrostatic spraying mechanism 4, powder conveying mechanism, and all components and sensors required by the control module are functioning properly. If a fault is found, the control module issues an alarm signal through its human-machine interface and indicates the location of the fault. After troubleshooting, the operator restarts the equipment. Based on the specifications of the metal sheet (substrate) to be sprayed (width 1000mm, thickness 2mm) and coating requirements (thickness 50μm, uniformity error ≤±2μm), the operator sets the initial spraying parameters through the human-machine interface: electrostatic field strength 50kV / m, powder conveying flow rate 30g / min, spraying distance 200mm, substrate 3 conveying speed 2m / min, and drying temperature 60℃. The control module 6 then sends the initial parameters to each actuator, completing the equipment initialization.

[0035] Step 2: Continuous conveying and pretreatment of substrate 3 The metal sheet to be coated is placed on the feed roller group 1 and the conveying roller group of the substrate conveying mechanism. The control module controls the variable frequency drive motor to start, which drives the conveying roller group to run. The side guide plate of the guide roller 2 is adjusted to a distance (1000mm) that matches the width of the sheet, and the upper and lower limit wheels are adjusted to a height (2mm) that matches the thickness of the sheet, to ensure that the sheet is conveyed smoothly and accurately. Before the sheet is conveyed to the coating area, it is treated by the surface dust removal module (high pressure air blowing) to remove dust and impurities from the surface of the sheet and improve the adhesion between the coating and the sheet.

[0036] Step 3: Powder pretreatment and stable conveying The powder in the powder storage bin enters the pre-treatment feeding assembly. First, it passes through a double-layer screen screening module. The upper screen filters out large impurities and agglomerated powder, while the lower screen refines the powder particle size, ensuring that the powder entering the conveying pipeline has a uniform particle size (≤0.1mm). The agglomerated powder that was screened out is crushed, and the crushed powder re-enters the filter for secondary screening. The hot air blower on the drying module is started, and hot air is blown in through the air inlet at the bottom of the gas channel 14. Then, the screened powder undergoes low-temperature drying treatment, with the drying temperature controlled at 60℃, reducing the powder humidity to below 5%. The pre-treated powder is conveyed to the powder distributor through the conveying pipeline. The flow control valve, spiral guide vanes, and conveying airflow (pressure 0.2MPa) work together to promote stable powder conveying and avoid blockage. The flow regulating valve 7 adjusts the powder supply rate (30g / min) for each spray gun according to the initial parameters.

[0037] Step 4: Optimization of Electrostatic Spraying and Electrostatic Field Dynamics The electrostatic generator is activated, supplying power to the annular multi-electrode structure of the electrostatic spraying mechanism 4. The electric field adjustment module adjusts the power supply parameters of the eight arc-shaped electrodes based on initial parameters (electrostatic field strength 50kV / m), creating a uniformly distributed electric field region on the surface of the substrate. In this embodiment, each arc-shaped electrode uses an independent power supply scheme. When the annular electrode has a median diameter of 50mm and a cross-sectional diameter of 6mm, the resulting electric field helps improve the atomization effect of the coating and makes the film thickness distribution more uniform. The spray gun assembly is activated, atomizing and spraying the powder. The powder particles are uniformly adsorbed onto the substrate surface under the action of the electrostatic field. Simultaneously, the electrostatic field strength sensor collects the electrostatic field strength distribution data in real time and transmits it to the control module. The control module analyzes the data using control methods. If the electrostatic field strength deviation in a certain area exceeds ±1kV / m, the electric field adjustment module 8 automatically adjusts the power supply voltage and current of the corresponding arc-shaped electrode, dynamically optimizing the electrostatic field distribution to ensure coating uniformity.

[0038] Step 5: Real-time monitoring and automatic parameter optimization of the spraying process The control module's sensors collect key parameters in real time during the spraying process: electrostatic field strength, powder flow rate, spraying distance, substrate velocity, ambient temperature and humidity, and coating thickness. The data acquisition unit performs noise reduction and filtering on the collected data, and then transmits it to the control module in real time through the data transmission unit. The control module uses a deep reinforcement learning-based control method to analyze each parameter in real time and compare it with preset parameter thresholds. If the powder flow rate deviation exceeds ±0.5 g / min, the flow regulation valve 7 and conveying pressure of the powder conveying mechanism 4 are automatically adjusted to ensure stable powder supply. If the spraying distance deviation exceeds ±0.1 mm, the lifting adjustment unit of the spray gun is automatically adjusted to ensure that the spraying distance is maintained at 200 mm. If the substrate speed deviation exceeds ±0.01 m / min, the speed of the variable frequency drive motor is automatically adjusted to maintain the substrate speed at 2 m / min. If the coating thickness deviation exceeds ±0.5 μm, the arc electrode power supply parameters and powder supply are comprehensively adjusted in combination with parameters such as electrostatic field strength and powder flow rate to ensure that the coating thickness meets the standard. At the same time, the control method continuously learns from real-time data and historical data to optimize control parameters and improve spraying quality and production efficiency.

[0039] Step 6: Spraying Completion and Post-treatment After the substrate is coated, it is conveyed by the substrate conveying mechanism to the curing area (curing temperature 180℃, curing time 20min) for curing. After curing, it is conveyed to the discharge area, completing the entire coating process. At the same time, the control module records the various parameter data and product quality data of this coating, updates the parameter database, and provides a reference for the coating of similar substrates in the future. During the operation of the equipment, if the pressure in the conveying pipeline exceeds 0.3MPa (risk of blockage), the control module will issue an alarm signal in time, stop the operation of the powder conveying mechanism, and the operator will open the anti-blockage valve to clear the blockage powder. After the treatment is completed, the equipment will resume normal operation to ensure production continuity.

[0040] The control method in this embodiment achieves efficient, stable, and continuous spraying of metal sheets, with coating uniformity error ≤ ±1.5μm, powder utilization rate ≥ 99%, continuous equipment operation time ≥ 8000 hours, product qualification rate ≥ 99.5%, and energy consumption reduced by more than 25% compared to traditional equipment. This significantly improves production efficiency and product quality, and reduces production costs and environmental pressure.

[0041] In steps 4 and 5, the control method based on deep reinforcement learning is specifically implemented as follows: (a) Definition of state space Define the input state vector of the control module as S = [S1, S2, S3, S4, S5, S6, S7, S8], where: S1: Electrostatic field strength distribution vector, which includes real-time readings from 6 electrostatic field strength sensors uniformly arranged along the substrate conveying direction, with a dimension of 6; S2: Real-time powder flow rate of each spray gun, with the same dimension as the number of spray guns; S4: Real-time spraying distance of each spray gun, with the same dimension as the number of spray guns; S5: Real-time value of substrate conveying speed; S6: Real-time values ​​of coating thickness in each area, collected by coating thickness sensors, with the same dimension and number of detection points; S7: Real-time ambient temperature and humidity; S8: Characteristic value of powder particle size distribution.

[0042] The total dimension of the state space is 6 + n + n + 1 + m + 1 + 1 + 1 = 2n + m + 10 (where n is the number of spray guns and m is the number of coating thickness detection points).

[0043] (ii) Definition of Action Space Define the output action vector of the control module as A = [a1, a2, a3, a4, a5], where: a1: The power supply voltage adjustment for each arc electrode, with 8 dimensions, and each adjustment range is -5kV to +5kV, continuously adjustable; a2: The adjustment range of the flow control valve for each spray gun, with the same dimension as the number of spray guns, and each adjustment range is -10% to +10%; a3: Spraying distance adjustment for each spray gun, the dimension is the same as the number of spray guns, and the range of each adjustment is -10mm to +10mm; a4: Substrate conveying speed adjustment range, from -0.5m / min to +0.5m / min; a5: Adjustment of drying temperature for powder pretreatment components, ranging from -10℃ to +10℃.

[0044] The action space is a continuous action space with a total dimension of 8 + n + n + 1 + 1 = 2n + 10.

[0045] (III) Reward Function Design The reward function R for reinforcement learning is defined as follows: R = α·R_ uniformity + β·R_ efficiency + γ·R_ stability - δ·R_penalty in: R_uniformity = -σ²(Thickness), which is the negative value of the coating thickness distribution variance. σ²(Thickness) is the variance of the coating thickness at each detection point on the substrate surface. The smaller this value (the more uniform the coating), the higher the reward. R_efficiency = η, which is the powder application rate (the ratio of the mass of the powder adhering to the total mass of the powder sprayed out). The higher this value, the higher the reward. R_stability = -|Q_actual - Q_target| / Q_target - |V_actual - V_target| / V_target, which is the normalized negative value of powder flow rate deviation and substrate velocity deviation; R_penalty = I(spark) + I(blockage), which is the penalty for spark breakdown or pipe blockage. α, β, γ, and δ are weight coefficients, satisfying α + β + γ + δ = 1, preferably α=0.4, β=0.3, γ=0.2, and δ=0.1.

[0046] (iv) Network Structure The Deep Deterministic Policy Gradient (DDPG) algorithm framework is adopted, including: Actor Network (Policy Network): Input is a state vector S (dimension 2n+m+10), output is an action vector A (dimension 2n+10). The network structure is: Input layer → Fully connected layer (256 neurons, ReLU activation) → Fully connected layer (128 neurons, ReLU activation) → Output layer (tanh activation, output mapped to the action space). Critic Network (Q Network): The input is a concatenation of the state vector S and the action vector A, and the output is the Q-value. The network structure is: Input layer → Fully connected layer (256 neurons, ReLU activation) → Fully connected layer (128 neurons, ReLU activation) → Output layer (linear activation, output Q-value); An experience replay mechanism is adopted, with a replay buffer capacity of 100,000 experiences. A soft update strategy using the target network is adopted, with an update rate τ = 0.001; The exploration strategy employs OU noise (Ornstein-Uhlenbeck process) or Gaussian noise.

[0047] (V) Training Methods Offline training phase: Pre-training is performed based on historical spraying data (including state-action-reward sequences) to achieve initial network convergence. Online fine-tuning phase: During actual equipment operation, after each spraying cycle (i.e., completing the spraying of one substrate), the state-action-reward data for that cycle is stored in the experience replay buffer. Small batches of randomly sampled data (batch size=64) are used to update the network parameters. Continuous self-learning optimizes control parameters, improving spraying quality and production efficiency.

[0048] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the appended claims.

Claims

1. A high-efficiency, stable, continuous electrostatic powder coating equipment, characterized in that, include: Main frame; A substrate conveying mechanism, which is installed on the main frame, conveys the substrate to be sprayed; An electrostatic spraying mechanism is disposed on the substrate conveying mechanism and is used to spray the substrate on the substrate conveying mechanism. A powder conveying mechanism is connected to the electrostatic spraying mechanism and is used to supply powder to the electrostatic spraying mechanism. The powder conveying mechanism includes a powder storage bin and a feeding pretreatment component disposed at the bottom of the powder storage bin. The feeding pretreatment component screens, crushes and dries the powder material in order to ensure stable conveying of the powder material. The control module detects the parameters inside the electrostatic spraying mechanism and controls the magnitude of the parameters to ensure that the electrostatic spraying mechanism meets the requirements of controllability and versatility in substrate spraying.

2. The high-efficiency, stable, continuous electrostatic powder coating equipment according to claim 1, characterized in that, The substrate conveying mechanism includes a feed roller group and a discharge roller group, which are rotatably connected to the main frame. The substrate is wound around the feed roller group and the discharge roller group for conveying. The feed roller group is equipped with a drive motor, which drives the feed roller group and the discharge roller to rotate. The substrate passes through the electrostatic spraying mechanism.

3. The high-efficiency, stable, continuous electrostatic powder coating equipment according to claim 1, characterized in that, The electrostatic spraying mechanism includes a spray gun assembly, an electrostatic generator, and an electrostatic field optimization component; wherein, the spray gun assembly is evenly arranged along the substrate conveying direction, and each spray gun corresponds to an independent adjustment unit, which can individually adjust the spraying angle, spraying distance, and spraying amount.

4. The high-efficiency, stable, continuous electrostatic powder coating equipment according to claim 3, characterized in that, The powder transfer mechanism includes: Powder storage bin; A pre-treatment feeding assembly, located at the bottom of the powder storage bin, is used to screen, crush, and dry the powder material. The conveying pipeline is used to connect the spray gun assembly and the feed pretreatment component for conveying powder materials. Each spray gun has a branch pipeline at its feed inlet. The conveying pipeline also includes a main pipeline, and the branch pipelines are connected to the main pipeline. A flow regulating valve is installed on each of the branch pipes to individually control the flow rate of the powder.

5. The high-efficiency, stable, continuous electrostatic powder coating equipment according to claim 4, characterized in that, The feed pretreatment component includes: The main housing has a filter element for filtering powdered materials inside. The main housing has a sieve material channel outside the filter element. The sieve material enters the sieve material channel from the top of the filter element. The top of the sieve material channel has a guide part that guides the airflow inside the sieve material channel to the filter element. The crushing component is rotatably connected to the inside of the screen material channel to crush the screen material entering the screen material channel; The drying element is connected to the bottom of the screen material channel, supplies high-pressure drying gas to the inside of the screen material channel, and blows the crushed screen material back into the top of the filter element.

6. The high-efficiency, stable, continuous electrostatic powder coating equipment according to claim 5, characterized in that, The main housing has a tapered opening at the top and a central channel inside. The top of the central channel is in close contact with the bottom surface of the filter element. The main housing includes an outer shell and an inner shell. The central channel is formed inside the inner shell, and the screen material channel is formed between the outer shell and the inner shell.

7. The high-efficiency, stable, continuous electrostatic powder coating equipment according to claim 6, characterized in that, The bottom of the screen material channel is provided with a gas channel, and the top of the gas channel is provided with a number of evenly arranged air blowing ports. The crushing component is provided on the top of the air blowing ports. The crushing component includes an inner ring and an outer ring that are closely attached to the inner and outer walls of the screen material channel. Crushing blades are provided between the inner and outer rings. The crushing component rotates inside the screen material channel under the action of external force.

8. The high-efficiency, stable, continuous electrostatic powder coating equipment according to claim 6, characterized in that, The filter element includes an upper filter screen and a lower filter screen that are fixed to each other and installed vertically. The top of the upper filter screen and the lower filter screen are respectively provided with an upper guide plate and a lower guide plate. A rotating motor that drives the filter element to rotate is fixedly installed on the inner shell. The diameter of the filter element is larger than the bottom diameter of the conical opening and smaller than the maximum diameter of the material channel on the screen.

9. A control method for the high-efficiency, stable, continuous electrostatic powder coating equipment according to any one of claims 1 to 8, characterized in that, Includes the following steps: Step 1: Equipment initialization and parameter setting. Initialize the control module and set the initial spraying parameters, including electrostatic field strength, powder conveying flow rate, spraying distance, substrate conveying speed, drying temperature, etc. The control module sends the initial parameters to each actuator to complete the equipment initialization. Step 2: Continuous conveying and pretreatment of substrate. Place the substrate to be sprayed on the substrate conveying mechanism, start the drive motor to drive the conveying roller group, and position and guide the substrate to ensure stable and accurate conveying of the substrate. Step 3: Powder pretreatment and stable conveying. The powder in the powder storage bin enters the feeding pretreatment component, where the powder material is screened, crushed and dried. Step 4: Electrostatic spraying and dynamic optimization of the electrostatic field. The electrostatic generator is started, and the electric field adjustment module adjusts the power supply parameters of each arc electrode according to the initial parameters to form a uniformly distributed electrostatic field. The spray gun assembly is started, and the powder is atomized and sprayed out. The powder particles are uniformly adsorbed on the surface of the substrate under the action of the electrostatic field. At the same time, the electrostatic field strength sensor collects the electrostatic field strength distribution data in real time and transmits it to the control module. The control module analyzes the data through control methods. If uneven electrostatic field distribution is detected, the electric field adjustment module is automatically controlled to adjust the power supply parameters of each arc electrode to dynamically optimize the electrostatic field distribution. Step 5: Real-time monitoring and automatic parameter optimization of the spraying process. The sensors of the control module collect key parameters in real time during the spraying process. At the same time, the collected data is processed by noise reduction and filtering, and transmitted to the control module in real time through the data transmission unit. The control module uses a control method based on deep reinforcement learning to analyze the parameters in real time, compare them with preset parameter thresholds, and output action vectors to adjust each actuator. Step 6: Spraying Completion and Post-processing. After the substrate is sprayed, it is transported by the substrate conveying mechanism to the curing area for curing. After curing, it is transported to the discharge area to complete the entire spraying process. At the same time, the control module records the various parameter data and product quality data of this spraying, updates the parameter database, and provides a reference for subsequent spraying. If problems such as pipe blockage or electrode failure are detected during equipment operation, the control module will issue an alarm signal in a timely manner and stop the operation of the relevant mechanisms.

10. The control method according to claim 9, characterized in that, In step 5, if a powder flow deviation is detected, the flow regulating valve and conveying pressure of the powder conveying mechanism are automatically adjusted to ensure stable powder supply and avoid blockage. If a spraying distance deviation is detected, the position of the spray gun is automatically adjusted to ensure that the spraying distance meets the set requirements. If a substrate speed deviation is detected, the speed of the variable frequency motor of the substrate conveying mechanism is automatically adjusted to achieve precise matching between the spraying rhythm and the conveying speed. If a coating thickness deviation is detected, the parameters of the relevant actuators are comprehensively adjusted in combination with parameters such as electrostatic field strength and powder flow to ensure that the coating thickness meets the standard. At the same time, the control method continuously learns from real-time data and historical data to optimize control parameters and improve spraying quality and production efficiency.

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