Spray gun for electrostatic powder spraying

Abstract

The invention relates to the field of spraying, in particular to an electrostatic powder spraying gun which comprises a panel, a mounting plate, a fixing plate, spraying pipes and an air pump, the multiple spraying pipes are evenly and elastically mounted on the fixing plate through first springs, a rack is fixedly mounted on each spraying pipe, and multiple pawls matched with the racks are evenly mounted on the mounting plate. A plurality of fixing assemblies are evenly arranged on the panel and correspond to the spray pipes one to one, when the air pump is started, the fixing assemblies clamp the spray pipes, and when the air pump is closed, the fixing assemblies release the fixing of the spray pipes and drive the pawls to be separated from the racks upwards, and the pawls are connected with reset assemblies. When the first springs push the spray pipes to reset slowly, the reset assemblies drive the pawls to be downwards connected with the racks, the electromagnetic valves and the control assemblies are fixedly installed on the spray pipes, when the workpieces push the spray pipes, the control assemblies control the electromagnetic valves on the corresponding spray pipes to be opened, the distances between the positions to be sprayed and the spray guns are kept equal, and therefore the purpose of uniform powder receiving is achieved.

Description

Technical Field

[0001] This invention relates to the field of spraying technology, specifically to a spray gun for electrostatic powder spraying. Background Technology

[0002] Electrostatic powder coating is a new technology that utilizes the principle of mutual attraction between positive and negative charges to uniformly coat resin powder onto the surface of a workpiece. It is then cured at high temperature to create a high-concentration coating on the workpiece surface. This technology is widely used in many industries, including metal products, furniture, machinery, and automobiles.

[0003] Compared with other spraying equipment, existing electrostatic powder coating equipment has the advantages of energy saving and environmental protection. It can effectively connect a series of processes such as spraying, recycling, and powder supply, thereby improving efficiency and reducing labor costs. While powder electrostatic spraying equipment boasts numerous advantages, it also suffers from several drawbacks, such as: surface discoloration, changes in gloss after curing, surface particles, bubbles and pinholes, and severe orange peel texture. The main causes of these defects include: uneven coating due to inconsistent distance between the spray nozzle and the workpiece; electrical penetration due to the nozzle being too close to the workpiece; and coatings that are too thin or too thick. Thin coatings exhibit muscle-like wrinkles, while thick coatings show mottled orange peel texture. Currently, when spraying irregularly shaped workpieces, the varying distances from the nozzle to different parts of the workpiece result in poor spraying quality. Therefore, manual spraying is often used to ensure quality for irregularly shaped workpieces. However, manual spraying is costly, inefficient, and requires highly skilled workers. Furthermore, the powder used in the spraying process can easily damage workers' health. Therefore, there is an urgent need to design a powder electrostatic spraying gun that maintains an equal distance between the workpiece and the spray gun during spraying, thereby improving the spraying quality. Summary of the Invention

[0004] The purpose of this invention is to provide a powder electrostatic spray gun that maintains an equal distance between the spraying position and the spray gun during the spraying process of irregularly shaped workpieces, thereby achieving uniform powder application and keeping the distance between the workpiece to be sprayed and the spray gun constant, thus improving the spraying quality of powder electrostatic spraying.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A powder electrostatic spray gun includes a panel, a mounting plate, a fixing plate, spray nozzles, and an air pump. The panel, mounting plate, and fixing plate are parallel and located on the same horizontal line. Multiple spray nozzles are uniformly and elastically mounted on the fixing plate via springs. Each spray nozzle is fixedly mounted with a rack. Multiple pawls that cooperate with the racks are uniformly mounted on the mounting plate to achieve unidirectional movement. Multiple fixing components are uniformly arranged on the panel, and each fixing component corresponds to a spray nozzle. When the air pump is started, the fixing components clamp the spray nozzles. When the air pump is turned off, the fixing components release the fixing of the spray nozzles and drive the pawls upward to disengage from the racks. A reset component is connected to the pawls. When the spring pushes the spray nozzles to slowly reset, the reset component drives the pawls downward to connect with the racks. Each spray nozzle is fixedly mounted with a solenoid valve and a control component is connected to each spray nozzle. When the workpiece pushes the spray nozzle, the control component controls the solenoid valves to open, thereby achieving selective spraying. This invention achieves uniform powder application on the workpiece surface by pushing the nozzle with the workpiece and clamping the nozzle with the fixing component. This ensures that the distance from each part of the workpiece to the nozzle is equal. After the workpiece pushes the nozzle, the workpiece returns to a specified distance.

[0007] Since the pawl and rack are usually meshed together and achieve transmission and positioning through the cooperation between the tooth groove and the tooth shape, in order to better realize this function, the accuracy requirements of the rack and pawl are put forward. To ensure that the meshing between the two can be carried out normally and that excessive gaps are not generated, the tooth width of the rack is set to be greater than or equal to the width of the pawl to prevent uneven force on the pawl during rotation.

[0008] The fixing components located inside the panel include a second spring, a clamping plate, and a mounting base. Multiple mounting slots are evenly spaced on the panel, and a mounting base is fixedly installed in each slot. Circular through holes, allowing the nozzle to pass through, are evenly spaced on the panel and can cooperate with the clamping plate. Each mounting base has two symmetrically arranged piston chambers, one end of which communicates with the through holes. A clamping plate is slidably connected to each of the two piston chambers via the second spring. The upper and lower parts of the piston chambers are axially symmetrical. The two clamping plates work together to clamp the nozzle, allowing for simultaneous clamping and loosening of the nozzle. The ends of the two piston chambers furthest from the nozzle are connected to an air pump. When the air pump is activated, gas enters the piston chambers furthest from the nozzle, clamping the nozzle. Two symmetrical connecting holes are provided at the ends of the two piston chambers away from the nozzle. The axes of the two connecting holes are parallel to the spring and both connecting holes are connected to the air pump. The parallelism of the connecting hole axes with the spring prevents gas from directly blowing onto the spring, causing spring failure and equipment malfunction. The two connecting holes are provided to ensure uniform force on both ends of the clamping plate and prevent excessive unidirectional friction between the clamping plate and the piston chamber. Multiple piston cylinders are uniformly fixedly installed on the mounting plate. A piston rod is movably installed in each piston cylinder, and pawls are installed at the bottom end of the corresponding piston rod. The bottom end of the piston cylinder is connected to the end of the piston chamber away from the nozzle, and the top end of the piston cylinder is connected to the air pump. When the air pump is turned on, the gas pushes the piston rod downward and clamps the nozzle. When the air pump is turned off, the gas enters the bottom of the piston cylinder from the end of the piston chamber away from the nozzle under the action of the second spring pulling the clamp plate to reset. This causes the pawl to move upward and is pushed by the first spring to reset the nozzle. No manual intervention or additional drive equipment is required to separate the pawl from the rack. The gas action enables linkage and a higher degree of automation.

[0009] To facilitate clamping the nozzle, the clamping plate is arc-shaped near the nozzle, and does not affect the back-and-forth movement of the nozzle when the clamping plate is reset. Each spring is made of carbon steel and alloy steel, which have high elasticity and fatigue strength, and strong impact resistance. The bottom surface of each rack is arc-shaped to facilitate better fit with the nozzle.

[0010] The reset assembly includes a second piston cylinder and a piston plate. The fixed plate has evenly spaced mounting holes parallel to the circular through holes on the mounting plate and the fixed plate. A second piston cylinder is fixedly installed in each mounting hole, and a piston plate is movably installed in each second piston cylinder. A spring is fixedly connected to the end of each second piston cylinder, elastically connecting the spring to the piston plate. The other end of the piston plate is connected to the nozzle, and the spring drives the nozzle to move back and forth. A small hole is opened on the bottom wall of the first piston cylinder, communicating with the end of the second piston cylinder furthest from the nozzle. A one-way air intake valve connects the small hole to the second piston cylinder to control the gas flow direction, thereby affecting the movement of the nozzle. A one-way exhaust valve and a safety valve are installed at the end of the second piston cylinder furthest from the nozzle to protect the equipment from damage, ensuring high reliability and safety. The piston cylinder has a small circular hole at its bottom. During the reset process, the nozzle will quickly reset due to the pushing action of the spring. The small circular hole can prevent damage to the nozzle and other structures due to the nozzle resetting too quickly, and can also drive the pawl to reset downwards and connect with the rack. There is no need for manual pawl reset, and the degree of automation is high.

[0011] To limit the distance the nozzle pushes the workpiece, a boss is provided on the nozzle. This boss is fixedly installed above the nozzle, and its square face is parallel to the side of the panel. Each boss has a flat surface for contact with the panel, and each flat surface is equipped with a push-button switch that cooperates with the panel. Each push-button switch is connected to an indicator light. When the power supply is unstable or the voltage fluctuates significantly, the air pump may fluctuate, causing the nozzle position to change during spraying. Therefore, the push-button switches and indicator lights are used to provide timely warnings when the nozzle moves during spraying, thus ensuring that the spraying distance between the nozzle and the workpiece remains constant, further improving spraying quality. The bottom of the boss is arc-shaped for easy installation on the nozzle. To meet the spraying requirements of more irregularly shaped parts and to satisfy the stability and deformation limits of the nozzle, the distance the nozzle extends beyond the panel is set between 300mm and 450mm.

[0012] When the workpiece pushes the spray gun, not all spray guns will touch the workpiece. If selective spraying is not set, powder will be wasted. Therefore, in order to save powder and achieve selective spraying, a sensor or solenoid valve can be installed at the nozzle. When the workpiece touches the nozzle, the sensor is linked with the powder spraying switch to control the powder spraying switch and achieve selective powder spraying. However, since the sensor is quite sensitive, powder and small particles in the air will affect the performance of the sensor. Moreover, such a sensor is expensive, so it is not the optimal solution here.

[0013] Preferably, a solenoid valve is used in conjunction with the control component to achieve selective powder spraying. To achieve better linkage between the solenoid valve and the control component, the control component mainly includes two connectors and a conductive block. Two square connectors are symmetrically fixed on the inner wall of the piston cylinder, and both square connectors are located between the piston plate and the mounting plate. Both connectors are connected to a common power source. A conductive block for connecting the two connectors is fixedly installed on the outer wall of the spray pipe. The spray pipe portion near the piston plate is made of polyurethane material. The conductive block is connected to the flexible portion of the polyurethane material. When the spray pipe moves, the conductive block contacts the two connectors, triggering the control component. When the gas reaches the flexible portion, the flexible portion expands outward due to the influence of the gas, allowing the conductive block to contact the connectors. The design of the flexible portion does not affect the gas flow or the spraying quality, and it also enables the conductive block to contact the connectors and trigger the control component. Using a flexible portion can reduce the friction between the conductive block and the connectors when the spray pipe moves, and can improve the stability of the connection between the two when the conductive block and the connectors are in contact and energized.

[0014] To prevent repeated clamping of the nozzle and resulting severe wear, serrations are provided at the arc-shaped position of the clamping plate. Serrated grooves are fixed at positions corresponding to the nozzle and clamping plate. This not only prevents damage to the nozzle but also improves the clamping effect. A spring is connected to the serrated strip. To ensure better cooperation between the serrations and the serrated grooves without affecting the movement of the nozzle, the spring allows the serrations to move, rather than the serrated grooves on the nozzle. The purpose of the spring design is to improve the accuracy of nozzle positioning.

[0015] When the piston rod drives the pawl to move upward, the force exerted by the rack on the pawl is unidirectional, resulting in greater force on one side of the piston cylinder, which will cause severe wear on the side and affect the working effect. Therefore, a support block is fixedly installed at the bottom of the piston rod, and a connecting rod is movably installed at the bottom end of the support block. A roller is fixedly installed at the right end of the connecting rod. Multiple strip grooves that are evenly opened on the mounting plate and roll in connection with the rollers are arranged to facilitate the pawl to move up and down under the action of gas, thereby clamping and resetting the spray gun.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0017] 1. The purpose is to solve the problem of uneven powder coating on the surface of workpieces due to irregular shapes in the electrostatic powder coating equipment in the factory. Specifically, the workpiece pushes the spray nozzle, the unidirectional movement of the pawl, and the clamping of the fixing component all play the role of fixing the spray nozzle. This ensures that the distance from the spraying position to the spray gun remains constant during the spraying process of irregularly shaped workpieces, improves the spraying quality, and prevents changes in the electric field strength caused by changes in the spraying distance during the spraying process, which would affect the coating thickness and powder deposition efficiency.

[0018] 2. The ratchet and rack mechanism provides initial fixation of the nozzle. To prevent the nozzle from tilting downwards due to gravity, the fixing component further secures it. The reset component resets the nozzle, facilitating the start of the next work cycle. The numerous connected gas pipes enable the fixing, reset, and control components to work in tandem under the influence of gas, reducing manual labor, increasing automation, and saving costs.

[0019] 3. The elastic connection of the spray nozzle on the fixed plate and the small hole at the bottom of the piston cylinder are all designed to prevent the spring from failing due to excessively fast reset, which could cause malfunctions in the spraying equipment. The reset process design effectively ensures the smooth start of the next work cycle. Attached Figure Description

[0020] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0021] Figure 2 This is a side view of the present invention;

[0022] Figure 3 For the present invention Figure 2 Sectional view of AA;

[0023] Figure 4 For the present invention Figure 2 Sectional view of BB;

[0024] Figure 5 For the present invention Figure 3 Enlarged view of the structure of section D in the middle;

[0025] Figure 6 For the present invention Figure 2 Enlarged view of the structure of part A in the middle;

[0026] Figure 7 For the present invention Figure 4 Enlarged view of the structure of section C;

[0027] Figure 8 For the present invention Figure 2 Enlarged view of the structure of part B in the middle section.

[0028] In the diagram: 1. Panel; 2. Mounting plate; 3. Fixing plate; 4. Solenoid valve; 5. Nozzle; 6. Boss; 7. Pawl; 8. Rack; 9. Piston cylinder one; 10. Piston cylinder two; 11. Fixing assembly; 12. Piston rod; 13. Support block; 14. Connecting rod; 15. Roller; 16. Strip groove; 17. Push-button switch; 101. Spring one; 102. Piston plate; 103. Connector; 104. Conductive block; 105. Safety valve; 111. Spring two; 112. Clamping plate; 113. Mounting base; 114. Spring three; 115. Serrated groove; 116. Serrated edge. Detailed Implementation

[0029] Please see Figures 1 to 8 This invention provides a powder electrostatic spraying gun, the technical solution of which is as follows:

[0030] According to the reference Figure 1 , Figure 2 A powder electrostatic spray gun includes a panel 1, a mounting plate 2, a fixing plate 3, a spray pipe 5, and an air pump. First, the inner and outer diameters of the spray pipe 5 are measured. Based on the measured inner and outer diameters, circular through holes of the same size are evenly opened on the panel 1, the mounting plate 2, and the fixing plate 3. The diameter of the circular through holes is the outer diameter of the spray pipe 5. Therefore, the spray pipe 5 is matched with the corresponding circular through holes and passes through the panel 1, the mounting plate 2, and the fixing plate 3 in sequence.

[0031] According to the reference Figure 2 and 8 During the process of the workpiece pushing the nozzle 5, it first touches the solenoid valve 4. In order to save powder usage, avoid powder waste, and achieve selective powder spraying, a solenoid valve 4 with the same size as the inner and outer diameter of the nozzle 5 is installed at the nozzle opening of the nozzle 5, and a control component is installed at the other end of the nozzle 5. When the workpiece pushes the nozzle 5, it touches the control component connected to the solenoid valve 4, thereby controlling the powder spraying switch. Specifically, a control component is installed between the piston plate 102 and the mounting plate 2. Connectors 103 are installed at both ends of the control component. A flexible hose made of polyurethane is installed near the piston plate 102 of the nozzle 5. A conductive block 104 is connected to the flexible hose. When the workpiece pushes the nozzle 5 backward, gas enters the nozzle 5, causing the flexible hose of the nozzle 5 to expand, which in turn causes the conductive block 104 on the flexible hose to contact the connector 103, causing the solenoid valve 4 and the control component to be linked. This achieves the purpose of only spraying powder from the nozzle 5 that is touched by the workpiece. The linkage between the solenoid valve 4 and the control component achieves selective powder spraying and effectively avoids powder waste.

[0032] To meet the requirements of more irregularly shaped parts, the length of the nozzle 5 is important when the workpiece pushes it. If the nozzle 5 is too long, gravity will cause the part of the nozzle 5 extending out of the panel 1 to tilt downwards. If the nozzle 5 is too short, it cannot meet the needs of most irregularly shaped parts. Therefore, to solve the above problems, it is more appropriate to set the distance of the nozzle extending out of the panel 1 between 300mm and 450mm. In order to limit the distance the workpiece pushes the nozzle, an arc-shaped boss 6 is fixedly installed on the nozzle 5 near the solenoid valve 4. When the workpiece pushes the nozzle 5, the workpiece stops moving forward when the first boss 6 touches the panel 1.

[0033] A piston cylinder 9 is fixedly installed on the mounting plate 2. A piston rod 12 is slidably installed inside the piston cylinder 9. Due to the rearward movement of the nozzle 5, the pawl 7 moves unidirectionally on the rack 8. Under the action of the pawl 7 and the rack 8, the nozzle 5 is initially fixed. Therefore, a rack 8 is fixedly installed on the nozzle 5 between the mounting plate 2 and the fixing plate 3, and multiple pawls 7 that cooperate with the rack 8 are evenly installed on the mounting plate 2. During the backward movement of the nozzle 5, the pawls 7 move unidirectionally on the rack 8 and perform clamping functions. However, when the piston rod 12 drives the pawls 7 to move upward, the side of the piston cylinder 9 experiences a large force, which will cause severe wear on the side. Therefore, a support block 13 is installed below the piston rod 12, and a connecting rod 14 is installed at the lower end of the support block 13. A roller 15 is installed at the right end of the connecting rod 14, and a slot 16 is provided at the contact point between the mounting plate 2 and the roller 15. Due to the function of the support block 13, the side of the piston rod 12 that is slidably connected to the piston cylinder 9 is subjected to uniform force, and due to the setting of the roller 15, the piston rod 12 can still drive the pawls 7 to move up and down. The cooperation between the pawls 7 and the rack 8 achieves the initial fixation of the nozzle 5.

[0034] According to the reference Figure 1To ensure stable spraying of the nozzle 5 during the spraying process and maintain a set distance from the workpiece, a fixing component 11 is installed inside the panel 1 at the contact point between the panel 1 and the nozzle 5. The fixing component 11 mainly includes a second spring 111, a clamping plate 112, and a mounting base 113. Mounting grooves are opened at the contact point between the panel 1 and the nozzle 5, and mounting bases 113 of the same size as the mounting grooves are installed on the mounting grooves. The two ends of the mounting base 113 are fixedly installed with the same yield strength of the second spring 111, and the two ends of the second spring 111 are connected to the arc-shaped clamping plate 112 of the same shape and thickness. The clamping plates 112 on both sides are used to clamp the nozzle 5. In order to prevent damage to the nozzle 5 and improve the clamping effect of the nozzle 5, two piston chambers are symmetrically arranged on the mounting base 113, and the arc-shaped ends of the two piston chambers are connected to the circular through holes that mate with the nozzle 5. The ends of the two piston chambers away from the nozzle 5 are connected to the air pump, so that the nozzle 5 is automatically clamped under the action of gas. When the air pump starts, the fixing component 11 clamps the nozzle 5 to fix it, and the spraying operation begins. When the spraying operation stops, the air pump stops working, the fixing component 11 automatically resets, and drives the pawl 7 to move upward. Under the action of the spring 101, the nozzle 5 is slowly reset. The spring 101 pushes the nozzle 5 to reset and drives the pawl 7 downward, connecting with the rack 8 to reset the pawl 7 and start the next working cycle. The fixing component 11 and the reset component are linked under the action of gas, and the degree of automation is higher.

[0035] To prevent gas from entering the piston chamber and causing defects on the spring surface, resulting in cracks and fatigue marks, and ultimately causing spring breakage and failure, two symmetrical connecting holes are provided at the ends of the two piston chambers away from the nozzle 5. The axes of the two connecting holes are parallel to the spring 111, and both connecting holes are connected to the air pump. The purpose is to ensure that the force on both ends of the clamping plate 112 is uniform and to prevent excessive unidirectional friction between the clamping plate 112 and the piston chamber.

[0036] According to the reference Figure 5To prevent repeated clamping of the nozzle 5 and cause severe wear, and to detect whether the nozzle 5 moves during the spraying process, a serration 116 is provided at the arc-shaped position of the clamping plate 112. A spring 114 is installed inside the arc-shaped surface of the clamping plate 112, and the spring 114 is connected to the serration 116. A serrated groove 115 is provided at the corresponding position of the nozzle 5 and the clamping plate 112. That is, under the action of gas, the serration 116 and the serrated groove 115 cooperate to clamp the nozzle 5. The spring 114 is connected to the serration 116 to allow the serration 116 and the serrated groove 115 to cooperate better without affecting the movement of the nozzle 5. The spring 114 allows the serration 116 to move, rather than the serrated groove 115 on the nozzle 5, thus improving the positioning accuracy of the nozzle 5. Both the clamping plate 112 and the serration 116 play the role of fixing the nozzle 5 during the spraying process.

[0037] During the spraying process, when the power supply is unstable or the voltage fluctuates significantly, the air pump may experience fluctuations, causing the position of the spray nozzle 5 to change during spraying. Therefore, a push-button switch 17 is installed at the arc-shaped surface of the contact area between the boss 6 and the panel 1. Each push-button switch 17 is connected to an indicator light. When the boss 6 touches the panel 1, the push-button switch 17 controls the indicator light to illuminate; when the boss 6 moves away from the panel 1, the push-button switch 17 controls the indicator light to turn off. This allows for timely detection of any positional shift of the boss 6, accurately controlling the distance between the spray nozzle 5 and the workpiece, further ensuring spraying quality. Furthermore, the boss 6 also protects the spring 101, preventing the workpiece from pushing the spray nozzle 5 and causing excessive compression of the spring 101, which could lead to its failure. During the spraying process, the boss 6 not only serves as a limiter but also as a warning device.

[0038] According to the reference Figure 8 When the air pump is turned off, the nozzle 5 needs to be reset. Therefore, a reset assembly is provided. The reset assembly mainly includes a piston cylinder 2 10 and a piston plate 102. According to the inner and outer diameters and height of the piston cylinder 2 10, through holes at a specified distance are evenly opened inside the fixed plate 3. One end of the nozzle 5 is connected to a solenoid valve 4, and the other end of the nozzle 5 is fixedly connected to the piston plate 102. The piston plate 102 is slidably connected to the piston cylinder 2 10 by a spring 101. Under the drive of the spring 101, the nozzle 5 moves back and forth. A small hole is provided on the bottom wall of 9. The small hole is connected to the end of piston cylinder 2 10 away from nozzle 5. A one-way air intake valve is connected between the small hole and piston cylinder 2 10 to control the one-way flow of gas and prevent the pawl 7 from being affected by the flow of gas during the reset process. A one-way exhaust valve and a safety valve 105 are installed at the end of piston cylinder 2 10 away from nozzle. The setting of the one-way air intake valve and the one-way exhaust valve effectively prevents the flow of gas from affecting the reset of nozzle 5 and pawl 7 during the reset process.

[0039] According to the reference Figure 2 and 5 Since this invention aims to release the clamping plate 112 from fixing the nozzle 5 and cause the pawl 7 to disengage from the rack 8 and move upward, piston cylinders 9 are evenly installed on the mounting plate 2. Each piston cylinder 9 has a piston rod 12 slidably connected inside. The bottom end of the piston rod 12 is rotatably connected to the pawl 7, and the bottom end of the piston cylinder 9 is connected to the end of the piston chamber furthest from the nozzle 5. The top end of the piston cylinder 9 is connected to the air pump. The piston chamber and piston cylinder 9 are connected through an air passage, enabling the clamping and resetting of the nozzle 5. When the air pump is turned on, the gas pushes the piston rod 12 downward, clamping the nozzle 5. When the air pump is turned off, gas enters the bottom of piston cylinder 9 from the end of the piston chamber furthest from the nozzle 5. Under the action of spring 111, the pawl 7 moves upward, resetting the nozzle 5. To prevent the nozzle 5 from resetting too quickly and causing spring 101 to fail, a small circular hole is provided at the bottom of piston cylinder 9 to connect to the air pump.

[0040] The workpiece moves, pushing the nozzle 5 backward and touching the solenoid valve 4 switch until the first boss 6 on the nozzle 5 touches the panel 1. The workpiece stops moving forward and returns to a position 250mm-300mm away from the nozzle. During the backward movement of the nozzle 5, the pawl 7 moves unidirectionally on the rack 8. Under the action of the pawl 7 and the rack 8, the nozzle 5 is initially fixed.

[0041] At this time, the air pump is turned on, and gas enters the piston chamber at the end away from the nozzle 5. Under the action of the gas, the clamping plate 112 clamps the nozzle 5. As the workpiece pushes the nozzle 5 backward, the conductive block 104 on the nozzle 5 connects to the connector 103, triggering the control component. The control component controls the powder spraying switch, and the powder spraying process begins. Due to the function of the push-button switch 17, the push-button switch 17 will detect whether the nozzle 5 has moved during the spraying process.

[0042] When the spraying operation stops, gas enters the piston cylinder 19 near the nozzle 5 from the piston chamber near the nozzle 5. The reset of the clamping plate 112 causes the pawl 7 to lift upward. Gas then enters the piston cylinder 20 away from the nozzle 5 from the piston cylinder 19 near the nozzle 5, thus resetting the nozzle 5. Since there is a pipe connected to the air pump at the end of the piston cylinder 19 near the nozzle 5, the nozzle 5 can be slowly reset.

[0043] It will be understood by those skilled in the art that various changes and modifications can be made to the embodiments without departing from the principles of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A powder electrostatic spray gun, comprising a panel (1), a mounting plate (2), a fixing plate (3), a spray pipe (5), and an air pump, characterized in that, Multiple nozzles (5) are evenly and elastically mounted on the fixing plate (3) via springs (101). Each nozzle (5) is fixedly mounted with a rack (8). Multiple pawls (7) that cooperate with the racks (8) are evenly mounted on the mounting plate (2). Multiple fixing components (11) are evenly provided on the panel (1), and each fixing component (11) corresponds to a nozzle (5). When the air pump is started, the fixing components (11) clamp the nozzles (5). When the air pump is turned off, the fixing components (11) clamp the nozzles (5). The component (11) releases the fixation of the nozzle (5) and drives the pawl (7) upward to disengage from the rack (8). A reset component is connected to the pawl (7). When the spring (101) pushes the nozzle (5) to slowly reset, the reset component drives the pawl (7) downward to connect with the rack (8). A solenoid valve (4) is fixedly installed on each nozzle (5). A control component is connected to each nozzle (5). When the workpiece pushes the nozzle (5), the control component controls the solenoid valve (4) on the corresponding nozzle (5) to open.

2. The powder electrostatic spray gun according to claim 1, characterized in that: The fixing assembly (11) includes a second spring (111), a clamping plate (112), and a mounting base (113). Multiple mounting slots are evenly distributed on the panel (1), and a mounting base (113) is fixedly installed in each mounting slot. Each mounting base (113) has a through hole for the nozzle (5) to pass through. Each mounting base (113) has two symmetrically arranged piston chambers, with one end of each piston chamber communicating with the through hole. The clamping plate (112) is slidably connected to each of the two piston chambers via the second spring (111). The clamping plates (112) are used together to clamp the nozzle (5). The ends of the two piston chambers away from the nozzle (5) are connected to the air pump. Multiple piston cylinders (9) are uniformly fixed on the mounting plate (2). A piston rod (12) is movably installed in each piston cylinder (9). The piston rod (12) corresponds to the pawl (7) one by one, and the pawl (7) is installed at the bottom of the corresponding piston rod (12). The bottom of the piston cylinder (9) is connected to the end of the piston chamber away from the nozzle (5), and the top of the piston cylinder (9) is connected to the air pump.

3. The powder electrostatic spray gun according to claim 2, characterized in that: The reset assembly includes piston cylinder 2 (10) and piston plate (102). Multiple mounting holes are evenly provided on the fixing plate (3). Piston cylinder 2 (10) is fixedly installed in each mounting hole. Piston plate (102) is movably installed in each piston cylinder 2 (10). Piston plate (102) is fixedly installed on nozzle (5). The two ends of spring 1 (101) are respectively connected to piston plate (102) and piston cylinder 2 (10). A small hole is provided on the bottom wall of piston cylinder 1 (9). The small hole is connected to the end of piston cylinder 2 (10) away from nozzle (5). A one-way air intake valve is connected between the small hole and piston cylinder 2 (10). A one-way exhaust valve and a safety valve (105) are installed on the end of piston cylinder 2 (10) away from nozzle (5).

4. The powder electrostatic spray gun according to claim 2, characterized in that: Each nozzle (5) is fixedly equipped with a boss (6), each boss (6) is provided with a flat surface for fitting with the panel (1), each flat surface is equipped with a push-button switch (17) that cooperates with the panel (1), and each push-button switch (17) is connected with an indicator light.

5. The powder electrostatic spray gun according to claim 3, characterized in that: The control assembly includes two connectors (103) and a conductive block (104). Two connectors (103) are symmetrically fixed on the inner side wall of the piston cylinder (10), and both connectors (103) are located between the piston plate (102) and the mounting plate (2). A conductive block (104) for connecting the two connectors (103) is fixedly installed on the outer side wall of the nozzle (5). The contact point between the conductive block (104) and the connector (103) is a flexible hose.

6. The powder electrostatic spray gun according to claim 2, characterized in that: Two connecting holes are symmetrically provided at the ends of the two piston chambers away from the nozzle (5). The axes of the two connecting holes are parallel to the second spring (111), and the two connecting holes are connected to the air pump.

7. The powder electrostatic spray gun according to claim 2, characterized in that: The end of the clamp (112) near the nozzle (5) is movably mounted with a saw tooth (116) via a spring three (114). The part of the nozzle (5) that contacts the clamp (112) is provided with a saw tooth groove (115) that meshes with the saw tooth (116), and the elastic force of the spring three (114) is less than the elastic force of the spring one (101).

8. The powder electrostatic spray gun according to claim 2, characterized in that: A support block (13) is fixedly installed at the bottom of the piston rod (12). A connecting rod (14) is horizontally slidably installed at the bottom end of the support block (13) in a direction perpendicular to the movement of the piston rod (12). A pawl (7) is installed on the connecting rod (14). A roller (15) is installed at the right end of the connecting rod (14). Multiple strip grooves (16) that are evenly opened on the mounting plate (2) are tumblingly connected to the rollers (15).

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