A powder electrostatic spray gun with anti-drip function

Abstract

This invention discloses a powder electrostatic spray gun with anti-drip function, comprising a powder supply unit and a spray gun unit, which are fastened together. The powder supply unit includes a powder tank, an air pump, and a mixing component, which is connected to the powder tank and air pump via a pipe. The spray gun unit includes an electrostatic component, an anti-drip component, a separating component, and a nozzle assembly. One end of the electrostatic component is fastened to the mixing component, the end of the electrostatic component away from the mixing component is fastened to the anti-drip component, the end of the anti-drip component away from the electrostatic component is fastened to the separating component, and the end of the separating component away from the anti-drip component is fastened to the nozzle assembly. The anti-drip component of this invention can centrally recover residual powder inside the spray gun, preventing residual powder from dripping and polluting the environment when not in use. The separating component of this invention, by adjusting the powder density on the sprayed surface, both accelerates the spraying efficiency and saves spraying costs.

Description

Technical Field

[0001] This invention relates to the field of powder electrostatic spray gun technology, specifically to a powder electrostatic spray gun with anti-drip function. Background Technology

[0002] With the increasingly severe global environmental situation and ever-higher national environmental protection standards, the coating industry landscape has been transformed. Traditional spray painting, due to its significant pollution, has been gradually phased out, while powder coatings contain almost no VOCs, resulting in minimal environmental pollution and aligning with current development trends. Furthermore, electrostatic powder coating significantly outperforms traditional spray painting in terms of mechanical strength, adhesion, corrosion resistance, and aging resistance, while also being less expensive. Consequently, electrostatic powder coating is gaining a larger market share. However, with traditional electrostatic powder spray guns, powder tends to agglomerate due to prolonged accumulation in the powder canister, forming large particles that can lead to uneven coating when applied to the workpiece. Conversely, traditional electrostatic powder spray guns typically produce uniformly distributed powder before spraying, which then spreads in a fan shape upon exiting the spray gun. The powder on the outer edges has a larger spray angle, resulting in a longer spray distance and a larger coverage area per unit area. If the powder is evenly distributed, the central area will reach the spraying standard first, followed by the outer areas. This leads to powder waste and prolonged spraying time. Traditional electrostatic powder spray guns lack effective measures for recovering powder inside the barrel after use, easily resulting in powder dripping. Summary of the Invention

[0003] The purpose of this invention is to provide a powder electrostatic spray gun with anti-drip function to solve the problems mentioned in the background art.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a powder electrostatic spray gun with anti-drip function, comprising a powder supply unit and a spray gun unit, wherein the powder supply unit and the spray gun unit are fastened together; the powder supply unit includes a powder tank, an air pump, and a mixing component; the mixing component is connected to the powder tank and the air pump through a pipe; the spray gun unit includes an electrostatic component, an anti-drip component, a separation component, and a nozzle assembly; one end of the electrostatic component is fastened to the mixing component; the end of the electrostatic component away from the mixing component is fastened to the anti-drip component; and the end of the anti-drip component away from the electrostatic component is fastened to the separation component. The components are securely connected. The end of the separation component away from the anti-drip component is securely connected to the nozzle component. The mixing component includes a mixing tube, an air inlet tube, a powder supply hole, and a vibration component. One end of the mixing tube is securely connected to the air inlet tube, and the end of the mixing tube away from the air inlet tube is securely connected to the electrostatic component. The end of the air inlet tube away from the mixing tube is connected to an air pump via a pipe. A powder supply hole is provided on the side wall of the mixing tube near the air inlet tube, and the powder supply hole is connected to the powder tank via a pipe. A vibration component is also provided on the side wall of the mixing tube between the powder supply hole and the electrostatic component, and the vibration component is located inside the side wall of the mixing tube. In this invention, air is supplied to the air inlet tube by an air pump. The air inlet tube delivers the gas to the mixing tube. During the rapid flow of the gas, a negative pressure is generated at the powder supply hole, and the powder in the powder tank is sucked into the mixing tube. The airflow mixes with the powder and passes through the vibration component. The vibration component performs graded vibration to separate the powder. The powder acquires a negative charge in the electrostatic component and is then sprayed out from the nozzle component and adsorbed onto the surface of the workpiece. The anti-drip component of this invention can centrally collect and recover residual powder inside the spray gun, preventing residual powder from dripping and polluting the environment when not in use. The separation component of this invention, by adjusting the powder density on the sprayed surface, both accelerates spraying efficiency and saves spraying costs.

[0005] Furthermore, the vibrating component includes an inner cavity, an air inlet hood, a vibrating plate, a guide plate, a transmission spring, and a guide groove. The inner cavity is located in the side wall of the mixing pipe, and has openings at both ends that are connected to the interior of the mixing pipe. The opening at the end of the inner cavity near the powder supply hole is connected to the air inlet hood, and the opening of the air inlet hood faces the powder supply hole. A vibrating plate is also provided on the inner wall of the mixing pipe, with one side of the vibrating plate in contact with the interior space of the mixing pipe and the other side in contact with the interior space of the inner cavity. The guide plate is located in the inner cavity and is perpendicular to the vibrating plate. Different transmission springs are connected to both ends of the guide plate. The side of the transmission spring at one end of the guide plate away from the guide plate is fastened to the vibrating plate, and the side of the transmission spring at the other end of the guide plate away from the guide plate is fastened to the side wall of the inner cavity. A guide groove is provided on the long side of the guide plate perpendicular to the vibrating plate, and the guide groove is zigzag-shaped. When the powder is drawn into the mixing tube, it is not all in the form of small particles. Due to long-term accumulation in the powder cylinder, some powder particles will agglomerate, forming large particles. When drawn into the mixing tube, the powder particles move rapidly with the airflow. Larger powder particles will fall during the rapid movement. This invention has a vibration component installed at the bottom of the mixing tube. The largest powder particles are located at the bottom and are collected by the air inlet hood. When the rapid airflow passes through the inner cavity, it passes through the guide groove on the guide plate. The zigzag guide groove guides the airflow to move up and down in a plane perpendicular to the vibration plate. During the up and down movement of the airflow, the guide plate will vibrate up and down. The vibration of the guide plate is transmitted to the vibration plate through the transmission spring. The vibration plate is made of elastic material, and it is also prone to self-excited flutter when high-speed airflow flows over both sides. The vibration of the vibration plate is fed back to the powder through the airflow. Since the large powder particles are formed by the agglomeration of multiple small powder particles, the amplitude of each small particle is different when affected by vibration. The vibration phase difference will cause the powder particles to separate. The largest particles experience the greatest vibration within the inner cavity, ensuring thorough separation. In the mixing tube, particles stratify, with larger particles moving closer to the vibrating plate under gravity, receiving greater vibrational energy in return. Smaller particles move further away, experiencing less vibration. This vibration pattern prevents normally agglomerated particles from being subjected to excessive vibration, thus avoiding unnecessary damage. Furthermore, the settling of previously clustered particles leads to uneven mixing of powder and airflow, resulting in a higher powder deposition at the bottom of the mixing tube. The vibration generated by the vibrating plate is primarily longitudinal, with the vibration direction near the inner side of the mixing tube extending vertically upwards. Separated powder moves upwards under vibration, filling gaps in the upper part of the tube, while powder in the inner cavity fills gaps at the bottom. This results in a more uniform powder distribution throughout the mixing tube, which facilitates better operation of subsequent electrostatic components.

[0006] Furthermore, the air inlet duct includes an outer pipe, an inner pipe, a connecting frame, and a circumferential inlet pipe. One end of the inner pipe is inserted into the outer pipe, and the end of the outer pipe away from the inner pipe is sealed. One end of the connecting frame is securely connected to the inner wall of the outer pipe, and the other end of the connecting frame is securely connected to the outer wall of the inner pipe. The end of the inner pipe away from the outer pipe is securely connected to the mixing pipe. The circumferential inlet pipe is securely connected to the side wall of the end of the outer pipe away from the inner pipe. The interior of the circumferential inlet pipe cuts into the interior of the outer pipe along the tangent direction. The end of the circumferential inlet pipe away from the outer pipe is connected to the air pump through a pipe. When gas enters the outer pipe from the circumferential inlet pipe, the airflow rotates and feeds along the side wall of the outer pipe. During the rotation, the airflow will generate centrifugal force on the impurity particles mixed in the airflow. The impurity particles will advance along the inner wall of the outer pipe. When the airflow reaches the inner pipe, the clean airflow in the inner layer will be input into the inner pipe, while the impurity particles will be mixed with the outer airflow and discharged from the gaps in the connecting frame. This invention greatly improves the cleanliness of the spray gun airflow in this way, preventing external impurities from mixing into the spray powder.

[0007] Furthermore, the electrostatic assembly includes a high-voltage generator and a mounting tube. One end of the mounting tube is securely connected to the mixing tube, and the end of the mounting tube away from the mixing tube is securely connected to an anti-drip assembly. The high-voltage generator is mounted on the inner wall of the mounting tube. During operation, the high-voltage generator generates a high-voltage, low-current electric field. Powder particles moving within this field acquire negative charges, and the uniform distribution of the powder promotes a uniform distribution of charge. When the workpiece is connected to the positive terminal of the power supply during operation, the negatively charged powder actively adheres to the workpiece surface after being ejected.

[0008] Furthermore, the anti-drip assembly includes a delivery pipe, an annular airbag, telescopic rods, a return spring, an inlet rod, and an outlet rod. One end of the delivery pipe is securely connected to the electrostatic component, and the other end is securely connected to the separation component. An annular airbag is installed outside the delivery pipe, and several telescopic rods are installed inside the annular airbag. The telescopic rods are evenly arranged around the annular airbag. One end of the telescopic rod is securely connected to the inner side of the annular airbag near the delivery pipe, and the other end of the telescopic rod is securely connected to the inner side of the annular airbag away from the delivery pipe. A return spring is installed inside the telescopic rod, and both ends of the return spring are securely connected to both ends of the telescopic rod. Several inlet rods and outlet rods are installed on the annular airbag, and the inlet rods and outlet rods are connected to the delivery pipe. A one-way outlet valve is installed in the outlet rod, and a one-way inlet valve is installed in the inlet rod. The inlet rods and outlet rods extend into the annular airbag. Several annular holes are evenly arranged on the inlet rods and outlet rods, and a filter screen is installed in the annular hole on the outlet rod. When the spray gun is working normally, a rapid airflow passes through the delivery pipe, and some gas is drawn out of the annular airbag. At this time, the annular airbag is compressed, the telescopic rod retracts, and the return spring is also compressed. When the spray gun stops working, the return spring will cause the annular airbag to quickly return to its original position, and the annular airbag will draw air inward. The powder remaining inside the spray gun will be adsorbed into the annular airbag. The air outlet and air inlet rods prevent the inhaled powder from clogging the air inlet and outlet. The filter screen in the annular hole on the air outlet rod prevents the inhaled powder from being discharged from the air outlet rod during the next use. Powder that has been repeatedly drawn back can be collected and cleaned. This invention uses an anti-drip component to centrally collect the powder remaining inside the spray gun, avoiding residual powder dripping and polluting the environment when not in use.

[0009] Furthermore, the separation assembly includes mounting rings, separation cylinders, connecting plates, and separation chambers. There are several separation cylinders of different sizes, coaxially arranged, and nested within each other. The connecting plates are securely connected to each separation cylinder. Different mounting rings are installed at both ends of the outermost separation cylinder. One end of one mounting ring is securely connected to the anti-drip assembly, and the other end is securely connected to the nozzle assembly. Several separation chambers are formed between the separation cylinders. The opening spacing of the separation chambers near the anti-drip assembly gradually increases from the inside out, while the opening spacing of the separation chambers near the nozzle assembly remains equal from the inside out. Spiral guide strips are provided on the surface of the separation cylinders. After passing through a high-voltage electrostatic field, the powder acquires a negative charge. Under the influence of the interaction force between the charges, the powder tends to be more uniformly distributed. However, this distribution does not meet the requirements of spraying. The powder spreads in a fan shape when sprayed. The powder on the outer edge has a larger spray angle, resulting in a longer spray distance and a larger coverage area per unit area after spraying. If the powder is uniformly distributed, the central area will reach the spraying standard first, followed by the outer areas. In this process, an unreasonable powder distribution will prolong the spraying time and waste the spraying material. This invention divides the powder into several portions using a separation chamber. The outer separation chambers collect more powder. As the powder moves within the separation chamber, a spiral guide bar on the surface of the separation cylinder guides the airflow to rotate. During this rotation, the powder is subjected to centrifugal force and tends to concentrate outwards. However, due to the negative charge on the powder, it does not completely shift; the interaction force between charges hinders concentration. By changing the spiral angle of the guide bar, the powder distribution can be controlled. The powder in each separation chamber is ultimately discharged from the side where the opening spacing remains equal from the inside out. After remixing, the powder density in the outer ring is greater than that in the inner ring. Before the charge force significantly adjusts the distribution, the powder is ejected from the nozzle assembly, resulting in a more uniform powder distribution on the workpiece surface. This allows for spraying completion of all areas of the workpiece surface within a shorter time interval. This invention improves spraying efficiency and saves on spraying costs by adjusting the powder density of the sprayed surface.

[0010] Furthermore, the nozzle assembly includes an annular injection port and an annular electrode. One end of the annular injection port is securely connected to the separation assembly, and the annular electrode is disposed inside the wall of the annular injection port. When the spray gun is working, the annular electrode is connected to the positive terminal of the power supply, and negatively charged powder is ejected from the annular injection port. The annular electrode generates a lateral attraction force on the powder, with the powder in the outer ring experiencing the strongest attraction force and a larger lateral deflection angle. The powder in the inner ring experiences a weaker attraction force and a smaller lateral deflection angle. Through the joint adjustment of the nozzle assembly and the separation assembly, the powder can be evenly distributed upon reaching the workpiece surface. By adjusting the voltage on the annular electrode, the spray range can be precisely controlled, thereby enabling a single nozzle to adapt to different workpieces. This invention improves the overall versatility of the device in this way.

[0011] Compared with existing technologies, the beneficial effects achieved by this invention are as follows: The vibration component of this invention uses longitudinal vibration waves generated by a vibrating plate to separate the aggregated powder. Simultaneously, the separated powder, under the action of vibration, fills the gaps in the upper powder, while the powder in the inner cavity fills the gaps in the bottom powder, resulting in a more uniform powder distribution throughout the mixing tube. This uniform powder distribution facilitates better operation of the subsequent electrostatic components. The air inlet pipe of this invention uses centrifugal air intake to discharge external impurities, ensuring the cleanliness of the spray gun airflow and preventing external impurities from mixing into the sprayed powder. The anti-drip component of this invention can centrally collect residual powder inside the spray gun, preventing residual powder from dripping and polluting the environment when not in use. The separation component of this invention, by adjusting the powder density on the sprayed surface, both accelerates spraying efficiency and saves spraying costs. Attached Figure Description

[0012] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0013] Figure 1 This is a cross-sectional view of the overall structure of the present invention;

[0014] Figure 2 This is a schematic diagram of the working principle of the vibration component of the present invention;

[0015] Figure 3 yes Figure 2 A magnified view of part A;

[0016] Figure 4 This is a drawing of the intake pipe component of the present invention;

[0017] Figure 5 This is a cross-sectional view of the overall structure of the anti-drip component of the present invention;

[0018] Figure 6 This is a three-dimensional structural diagram of the separation component of the present invention;

[0019] Figure 7 This is a cross-sectional view of the overall structure of the separation component of the present invention;

[0020] Figure 8 This is a three-dimensional view of the overall structure of the present invention;

[0021] In the diagram: 1-Mixing assembly, 11-Mixing pipe, 12-Inlet pipe, 121-Outer pipe, 122-Inner pipe, 123-Connecting frame, 124-Circumferential inlet pipe, 13-Powder supply hole, 14-Vibration component, 141-Inner cavity, 142-Air inlet hood, 143-Vibration plate, 144-Guide plate, 145-Transmission spring, 146-Guide groove, 2-Electrostatic assembly, 21-High voltage generator, 23-Installation pipe, 3-Anti-drip assembly, 31-Conveying pipe, 32-Annular airbag, 33-Telescopic rod, 34-Reset spring, 35-Inlet rod, 36-Outlet rod, 4-Separation assembly, 41-Installation ring, 42-Separation cylinder, 43-Connecting piece, 44-Separation chamber, 5-Nozzle assembly, 51-Annular injection port, 52-Annular electrode. 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 some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] Please see Figure 1-8 The present invention provides the following technical solution:

[0024] like Figure 1 , 8As shown, a powder electrostatic spray gun with anti-drip function includes a powder supply unit and a spray gun unit, which are fastened together. The powder supply unit includes a powder tank, an air pump, and a mixing component 1. The mixing component is connected to the powder tank and the air pump through a pipe. The spray gun unit includes an electrostatic component 2, an anti-drip component 3, a separation component 4, and a nozzle assembly 5. One end of the electrostatic component 2 is fastened to the mixing component 1, the end of the electrostatic component 2 away from the mixing component 1 is fastened to the anti-drip component 3, the end of the anti-drip component 3 away from the electrostatic component 2 is fastened to the separation component 4, and the end of the separation component 4 away from the anti-drip component 3 is fastened to the nozzle assembly 5. Component 5 is fastened together. The mixing component 1 includes a mixing pipe 11, an air inlet pipe 12, a powder supply hole 13, and a vibration component 14. One end of the mixing pipe 11 is fastened together with the air inlet pipe 12. The end of the mixing pipe 11 away from the air inlet pipe 12 is fastened together with the electrostatic component 2. The end of the air inlet pipe 12 away from the mixing pipe 11 is connected to the air pump through a pipe. A powder supply hole 13 is provided on the side wall of the mixing pipe 11 near the air inlet pipe 12. The powder supply hole 13 is connected to the powder bucket through a pipe. A vibration component 14 is also provided on the side wall of the mixing pipe 11 between the powder supply hole 13 and the electrostatic component 2. The vibration component 14 is located inside the side wall of the mixing pipe 11. This invention uses an air pump to supply air into the air inlet pipe 12, which then delivers the gas to the mixing pipe 11. During the rapid gas flow, a negative pressure is generated at the powder supply hole 13, drawing powder from the powder container into the mixing pipe 11. The airflow, mixed with the powder, passes through the vibration component 14, which grades and vibrates the powder to separate it. The powder acquires a negative charge in the electrostatic component 2 and is then ejected from the nozzle assembly 5, adsorbing onto the workpiece surface. The anti-drip component 3 of this invention can centrally collect residual powder inside the spray gun, preventing residual powder from dripping and polluting the environment when not in use. The separation component 4 of this invention, by adjusting the powder density on the sprayed surface, both accelerates the spraying efficiency and saves spraying costs.

[0025] like Figure 2 , 3As shown, the vibrating component 14 includes an inner cavity 141, an air inlet hood 142, a vibrating plate 143, a guide plate 144, a transmission spring 145, and a guide groove 146. The inner cavity 141 is disposed in the side wall of the mixing tube 11. Openings are provided at both ends of the inner cavity 141, and these openings communicate with the interior of the mixing tube 11. The opening at the end of the inner cavity 141 near the powder supply hole 13 is connected to the air inlet hood 142. The opening of the air inlet hood 142 faces the powder supply hole 13. A vibrating plate 143 is also disposed on the inner wall of the mixing tube 11. One side of the vibrating plate 143 contacts the interior space of the mixing tube 11. The other side of the vibrating plate 143... One side of the guide plate 144 is in contact with the internal space of the inner cavity 141. The guide plate 144 is located in the inner cavity 141 and is set perpendicular to the vibrating plate 143. Different transmission springs 145 are connected to both ends of the guide plate 144. The side of the transmission spring 145 located at one end of the guide plate 144 away from the guide plate 144 is fastened to the vibrating plate 143. The side of the transmission spring 145 located at the other end of the guide plate 144 away from the guide plate 144 is fastened to the side wall of the inner cavity 141. A guide groove 146 is provided on the long side of the guide plate 144 perpendicular to the vibrating plate 143. The guide groove 146 is zigzag-shaped. When the powder is drawn into the mixing tube 11, it is not all in the form of small particles. Due to the long-term accumulation in the powder cylinder, some powder will agglomerate with each other, and these powders will aggregate into large particles. When the powder particles are drawn into the mixing tube 11, they move rapidly with the airflow. Larger powder particles may fall during the rapid movement. The present invention provides a vibration component 14 at the bottom of the mixing tube 11. The largest powder particles are located at the bottom and are collected by the air inlet shroud 142. When the rapid airflow passes through the inner cavity 141, it passes through the guide groove 146 on the guide plate 144. The zigzag guide groove 146 guides the airflow to move up and down in a plane perpendicular to the vibration plate 143. During the up and down movement of the airflow, the guide plate 144 will vibrate up and down. The vibration of the guide plate 144 is transmitted to the vibration plate 143 through the transmission spring 145. The vibration plate 143 is made of elastic material and is prone to self-excited flutter when high-speed airflow flows over both sides. The vibration of the vibration plate 143 is fed back to the powder through the airflow. Since the large powder particles are composed of multiple small powder particles, the amplitude of each small particle is different when affected by vibration. The vibration phase difference will cause the powder particles to separate. The largest particles bear the greatest vibration in the inner cavity 141 and can be fully separated, while the particles in the mixing tube 11 will stratify. The larger particles will be closer to the vibrating plate 143 under the action of gravity, and the vibrating plate 143 will give back greater vibration energy accordingly. The smaller particles are away from the vibrating plate 143 and bear less vibration. This vibration mode can avoid unnecessary damage caused by excessive vibration to normally normal particles.On the other hand, the sedimentation of originally agglomerated particles will lead to uneven mixing of powder and airflow, and more powder will be deposited at the bottom of the mixing tube. The vibration generated by the vibrating plate 143 is mainly a longitudinal vibration wave. The vibration transmission direction of the side near the inside of the mixing tube is vertically upward. The separated powder will move upward under the action of vibration to fill the gap of the upper powder, while the powder in the inner cavity 141 will fill the gap of the bottom powder. The powder distribution in the entire mixing tube 11 will tend to be uniform. The uniform powder distribution can help the subsequent electrostatic component 2 to operate better.

[0026] like Figure 1 , 4 As shown, the air inlet pipe 12 includes an outer pipe 121, an inner pipe 122, a connecting bracket 123, and a circumferential inlet pipe 124. One end of the inner pipe 122 is inserted into the outer pipe 121, and the end of the outer pipe 121 away from the inner pipe 122 is sealed. One end of the connecting bracket 123 is tightly connected to the inner wall of the outer pipe 121, and the other end of the connecting bracket 123 is tightly connected to the outer wall of the inner pipe 122. The end of the inner pipe 122 away from the outer pipe 121 is tightly connected to the mixing pipe 11. The circumferential inlet pipe 124 is tightly connected to the side wall of the end of the outer pipe 121 away from the inner pipe 122. The interior of the circumferential inlet pipe 124 is cut into the interior of the outer pipe 121 along the tangent direction of the outer pipe 121. The end of the circumferential inlet pipe 124 away from the outer pipe 121 is connected to the air pump through a pipe. When gas enters the outer tube from the circumferential inlet pipe 124, the airflow rotates and feeds along the side wall of the outer tube 121. During this rotation, the airflow generates a centrifugal force on the impurity particles mixed in the airflow, causing them to adhere to the inner wall of the outer tube 121. When the airflow reaches the inner tube 122, the clean airflow in the inner layer is introduced into the inner tube 122, while the impurity particles, mixed with the outer airflow, are discharged through the gaps in the connecting frame 123. This invention significantly improves the cleanliness of the spray gun airflow in this way, preventing external impurities from mixing into the sprayed powder.

[0027] like Figure 1 As shown, the electrostatic component 2 includes a high-voltage generator 21 and a mounting tube 23. One end of the mounting tube 23 is securely connected to the mixing tube 11, and the end of the mounting tube 23 away from the mixing tube 11 is securely connected to the anti-drip component 3. The high-voltage generator 21 is mounted on the inner wall of the mounting tube 23. During operation, the high-voltage generator 21 generates a high-voltage, low-current high-voltage electric field. Powder particles moving within this field acquire negative charges, and the uniform distribution of the powder promotes a uniform distribution of charge. When the workpiece is connected to the positive terminal of the power supply during operation, the negatively charged powder actively adheres to the surface of the workpiece after being ejected.

[0028] like Figure 1 , 5As shown, the anti-drip assembly 3 includes a delivery pipe 31, an annular airbag 32, telescopic rods 33, a return spring 34, an inlet rod 35, and an outlet rod 36. One end of the delivery pipe 31 is fastened to the electrostatic assembly 2, and the other end of the delivery pipe 31 is fastened to the separation assembly 4. An annular airbag 32 is provided outside the delivery pipe 31, and several telescopic rods 33 are provided inside the annular airbag 32. The telescopic rods 33 are evenly arranged around the annular airbag 32. One end of the telescopic rod 33 is fastened to the inner side of the annular airbag 32 near the delivery pipe 31, and the other end of the telescopic rod 33 is fastened to the annular airbag 32 away from the delivery pipe 31. The inner side of the pipe 31 is fastened. A return spring 34 is installed inside the telescopic rod 33. The two ends of the return spring 34 are fastened to the two ends of the telescopic rod 33. The annular airbag 32 is provided with several air inlet rods 35 and air outlet rods 36. The air inlet rods 35 and air outlet rods 36 are connected to the delivery pipe 31. A one-way air outlet valve is installed in the air outlet rod 36, and a one-way air inlet valve is installed in the air inlet rod 35. The air inlet rods 35 and air outlet rods 36 extend into the annular airbag 32. Several annular holes are evenly arranged on the air inlet rods 35 and air outlet rods 36. A filter screen is installed in the annular hole on the air outlet rod 36. When the spray gun is working normally, a rapid airflow passes through the delivery pipe 31. Some gas is drawn out of the annular airbag 32. At this time, the annular airbag 32 is compressed, the telescopic rod 33 retracts, and the return spring 34 is also in a compressed state. When the spray gun stops working, the return spring 34 will cause the annular airbag 32 to quickly return to its original position. The annular airbag 32 will then draw air inward, and any residual powder inside the spray gun will be drawn into the annular airbag 32. The air outlet rod 36 and air inlet rod 35 prevent the sucked-in powder from clogging the air inlet and outlet. The filter screen installed in the annular hole on the air outlet rod 36 prevents the sucked-in powder from being discharged from the air outlet rod 36 during the next use. Powder sucked in multiple times can be collected and cleaned. This invention uses the anti-drip component 3 to centrally collect residual powder inside the spray gun, preventing residual powder from dripping and polluting the environment when not in use.

[0029] like Figure 6 , 7As shown, the separation assembly 4 includes mounting rings 41, separation cylinders 42, connecting plates 43, and separation chambers 44. There are several separation cylinders 42, each of different sizes, coaxially arranged, and nested within each other. The connecting plates 43 are securely connected to each separation cylinder 42. Different mounting rings 41 are installed at both ends of the outermost separation cylinder 42. One end of one mounting ring 41 is securely connected to the anti-drip assembly 3, and the other end is securely connected to the nozzle assembly 5. Several separation chambers 44 are formed between the separation cylinders 42. The opening spacing of the separation chambers 44 near the anti-drip assembly 3 gradually increases from the inside out, while the opening spacing of the separation chambers 44 near the nozzle assembly 5 remains equal from the inside out. Spiral guide strips are provided on the surface of the separation cylinders 42. After passing through a high-voltage electrostatic field, the powder acquires a negative charge. Under the influence of the interaction force between the charges, the powder tends to be further uniformly distributed. However, this distribution does not meet the requirements of spraying. When the powder is sprayed, it spreads in a fan shape. The powder on the outer side has a larger spray angle, so its spray distance is longer, and the coverage area per unit area after spraying is also larger. If the powder is evenly distributed, the middle area will reach the spraying standard first, and then the outer areas will reach the spraying standard. In this process, unreasonable powder distribution will prolong the spraying time and cause waste of spraying materials. This invention divides powder into several portions using separation chambers 44. The outermost separation chambers 44 collect more powder. As the powder moves within the separation chambers 44, a spiral guide strip on the surface of the separation cylinder 42 guides the airflow to rotate. During this rotation, the powder is subjected to centrifugal force, causing it to concentrate outwards. However, due to the negative charge on the powder, it does not completely shift; the interaction force between charges hinders concentration. By changing the spiral angle of the guide strip, the powder distribution can be controlled. The powder in each separation chamber 44 is ultimately discharged from the side where the opening spacing remains equal from the inside out. After remixing, the powder density in the outer ring is greater than that in the inner ring. Before the charge force significantly adjusts the distribution, the powder is ejected from the nozzle assembly 5, resulting in a more uniform powder distribution on the workpiece surface. This allows for coating completion on all parts of the workpiece surface within a shorter time interval. This invention, by adjusting the powder density on the coating surface, both accelerates coating efficiency and saves coating costs.

[0030] like Figure 1As shown, the nozzle assembly 5 includes an annular injection port 51 and an annular electrode 52. One end of the annular injection port 51 is fastened to the separation assembly 4, and the annular electrode 52 is disposed inside the wall of the annular injection port 51. When the spray gun is working, the annular electrode 52 is connected to the positive terminal of the power supply, and negatively charged powder is ejected from the annular injection port 51. The annular electrode 52 generates a lateral attraction force on the powder. The powder in the outer ring is subjected to the greatest attraction force, and the powder spray angle is larger. The powder in the inner ring is subjected to a smaller attraction force, and the powder spray angle is smaller. Through the joint adjustment of the nozzle assembly 5 and the separation assembly 4, the powder can be evenly distributed when it reaches the workpiece surface. By adjusting the voltage on the annular electrode 52, the spray range can be precisely controlled, thereby enabling a single nozzle to adapt to different workpieces. In this way, the invention improves the overall versatility of the device.

[0031] The working principle of this invention is as follows: When gas enters the outer tube from the circumferential inlet pipe 124, the airflow rotates along the side wall of the outer tube 121. During the rotation, the airflow generates a centrifugal force on the impurity particles mixed in the airflow, throwing the impurities to the outer layer. The clean airflow in the inner layer is then input into the inner tube 122. The airflow enters the mixing tube 11 and also draws the powder into the mixing tube 11. The vibration component 14 provided on the bottom side of the mixing tube 11 separates the agglomerated powder. After separation, the powder passes through the high-pressure generator 21 with the airflow, acquiring a negative charge. The airflow then passes through the anti-drip assembly 3 and enters the separation assembly 4. The separation chamber 44 divides the powder into several parts, with the outer separation chamber 44 collecting more powder. As the powder moves inside the separation chamber 44, the spiral guide strips on the surface of the separation cylinder 42 guide the airflow to rotate. During the rotation of the airflow, the powder is subjected to centrifugal force, causing it to concentrate outwards. The powder in each separation chamber 44 is eventually discharged from the side where the opening spacing is equal from the inside out. After remixing, the powder density in the outer ring is greater than that in the inner ring. The powder is finally ejected from the annular spray nozzle 51, and the annular electrode corrects the spray angle. When the spray gun stops working, the reset spring 34 causes the annular airbag 32 to quickly reset, and the annular airbag 32 draws air inwards, adsorbing the powder remaining inside the spray gun.

[0032] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0033] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A powder electrostatic spray gun having a drip prevention function, characterized by: The powder electrostatic spray gun comprises a powder supply unit and a spray gun unit, the powder supply unit and the spray gun unit are fixedly connected, the powder supply unit comprises a powder barrel, an air pump and a mixing assembly (1), the mixing assembly is communicated with the powder barrel and the air pump through a pipeline, the spray gun unit comprises an electrostatic assembly (2), an anti-dripping assembly (3), a separation assembly (4) and a nozzle assembly (5), one end of the electrostatic assembly (2) is fixedly connected with the mixing assembly (1), the end of the electrostatic assembly (2) away from the mixing assembly (1) is fixedly connected with the anti-dripping assembly (3), the end of the anti-dripping assembly (3) away from the electrostatic assembly (2) is fixedly connected with the separation assembly (4), and the end of the separation assembly (4) away from the anti-dripping assembly (3) is fixedly connected with the nozzle assembly (5), the mixing assembly (1) comprises a mixing pipe (11), an air inlet pipe (12), a powder supply hole (13) and a vibrating part (14), one end of the mixing pipe (11) is fixedly connected with the air inlet pipe (12), the end of the mixing pipe (11) away from the air inlet pipe (12) is fixedly connected with the electrostatic assembly (2), the end of the air inlet pipe (12) away from the mixing pipe (11) is connected with the air pump through a pipeline, the side wall of the mixing pipe (11) near the end of the air inlet pipe (12) is provided with the powder supply hole (13), the powder supply hole (13) is connected with the powder barrel through a pipeline, and the vibrating part (14) is arranged on the side wall of the mixing pipe (11) between the powder supply hole (13) and the electrostatic assembly (2), and the vibrating part (14) is arranged in the side wall of the mixing pipe (11); The vibration component (14) comprises an inner cavity (141), an air inlet cover (142), a vibration plate (143), a guide plate (144), a transmission spring (145), and a guide groove (146). The inner cavity (141) is arranged in the side wall of the mixing pipe (11), and both ends of the inner cavity (141) are provided with openings which are communicated with the inside of the mixing pipe (11). The opening arranged at the end of the inner cavity (141) close to the powder supply hole (13) is connected with the air inlet cover (142), and the opening of the air inlet cover (142) faces the powder supply hole (13). The inner wall surface of the mixing pipe (11) is further provided with the vibration plate (143), one side of the vibration plate (143) is in contact with the inside space of the mixing pipe (11), and the other side of the vibration plate (143) is in contact with the inside space of the inner cavity (141). The guide plate (144) is arranged in the inner cavity (141) and is perpendicular to the vibration plate (143). Different transmission springs (145) are connected to both ends of the guide plate (144). The transmission spring (145) located at one end of the guide plate (144) is tightly connected to the side of the vibration plate (143) away from the guide plate (144), and the transmission spring (145) located at the other end of the guide plate (144) is tightly connected to the side wall of the inner cavity (141) away from the guide plate (144). The guide groove (146) is arranged on the long side of the guide plate (144) which is perpendicular to the vibration plate (143), and the guide groove (146) is a broken line type.

2. The powder electrostatic spray gun with anti-dripping function according to claim 1, characterized in that: The air inlet pipe (12) comprises an outer connecting pipe (121), an inner connecting pipe (122), a connecting frame (123), and a circumferential inlet pipe (124). One end of the inner connecting pipe (122) is inserted into the outer connecting pipe (121), and the end of the outer connecting pipe (121) away from the inner connecting pipe (122) is sealed. One end of the connecting frame (123) is tightly connected to the inner wall of the outer connecting pipe (121), and the other end of the connecting frame (123) is tightly connected to the outer wall of the inner connecting pipe (122). The end of the inner connecting pipe (122) away from the outer connecting pipe (121) is tightly connected to the mixing pipe (11). The circumferential inlet pipe (124) is tightly connected to the side wall of the outer connecting pipe (121) away from the inner connecting pipe (122). The circumferential inlet pipe (124) is cut into the inner part of the outer connecting pipe (121) along the tangent direction of the outer connecting pipe (121), and the end of the circumferential inlet pipe (124) away from the outer connecting pipe (121) is communicated with the air pump through a pipeline.

3. The powder electrostatic spray gun with anti-dripping function according to claim 1, characterized in that: The electrostatic component (2) comprises a high-voltage generator (21) and a mounting pipe (23). One end of the mounting pipe (23) is tightly connected to the mixing pipe (11), and the end of the mounting pipe (23) away from the mixing pipe (11) is tightly connected to the anti-dripping component (3). The high-voltage generator (21) is mounted on the inner side wall of the mounting pipe (23).

4. The powder electrostatic spray gun with anti-dripping function according to claim 1, characterized in that: The anti-dripping assembly (3) comprises a conveying pipe (31), an annular air bag (32), an extension rod (33), a reset spring (34), an air inlet rod (35), and an air outlet rod (36). One end of the conveying pipe (31) is fixedly connected with the electrostatic assembly (2), and the other end of the conveying pipe (31) is fixedly connected with the separation assembly (4). The conveying pipe (31) is externally provided with the annular air bag (32). The annular air bag (32) is internally provided with a plurality of extension rods (33). The extension rods (33) are uniformly arranged around the annular air bag (32). One end of each extension rod (33) is fixedly connected with the inner side of the annular air bag (32) close to the conveying pipe (31), and the other end of each extension rod (33) is fixedly connected with the inner side of the annular air bag (32) away from the conveying pipe (31). The extension rods (33) are internally provided with reset springs (34). The reset springs (34) are fixedly connected with the two ends of the extension rods (33). The annular air bag (32) is provided with a plurality of air inlet rods (35) and air outlet rods (36). The air inlet rods (35) and the air outlet rods (36) are communicated with the conveying pipe (31). The air outlet rod (36) is provided with a one-way air outlet valve. The air inlet rod (35) is provided with a one-way air inlet valve. The air inlet rods (35) and the air outlet rods (36) extend into the annular air bag (32). A plurality of annular holes are uniformly arranged on the air inlet rods (35) and the air outlet rods (36). The annular holes arranged on the air outlet rod (36) are provided with a filter screen.

5. The powder electrostatic spray gun with anti-dripping function according to claim 1, characterized in that: The separation assembly (4) comprises a mounting ring (41), a separation cylinder (42), a connecting plate (43), and a separation cavity (44). The separation cylinder (42) has a plurality of sizes. The plurality of separation cylinders (42) are coaxially arranged. Different separation cylinders (42) are sleeved with each other. The connecting plate (43) is fixedly connected with each separation cylinder (42). The outermost separation cylinder (42) is provided with different mounting rings (41) at both ends. One end of one mounting ring (41) is fixedly connected with the anti-dripping assembly (3), and the other end of the other mounting ring (41) is fixedly connected with the nozzle assembly (5). A plurality of separation cavities (44) are formed between the plurality of separation cylinders (42). The opening spacing of the plurality of separation cavities (44) close to the anti-dripping assembly (3) gradually increases from inside to outside. The opening spacing of the plurality of separation cavities (44) close to the nozzle assembly (5) remains equal from inside to outside. The surface of the separation cylinder (42) is provided with a spiral guide strip.

6. The powder electrostatic spray gun with anti-dripping function according to claim 1, characterized in that: The nozzle assembly (5) comprises an annular jet port (51) and an annular electrode (52). One end of the annular jet port (51) is fixedly connected with the separation assembly (4). The annular electrode (52) is arranged inside the wall surface of the annular jet port (51).

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