Automatic spraying device for large wind power
By designing automated spraying devices for large wind power, using technical means such as cylinders, infrared imagers, fans, slide rails, automatic spray guns and electronically controlled telescopic rods, the problems of uniformity of spraying and health risks of large wind power workpieces and artificial spraying are solved, and efficient and uniform spraying effect is achieved.
Patent Information
- Application Number
- CN202411968300.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-30
- Publication Date
- 2025-04-11
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The prior art is difficult to achieve uniformity in spraying large wind power workpieces, and there are health risks for artificial painting.
An automated spraying device was designed, using technical means such as cylinders, infrared imagers, fans, slide rails, automatic spray guns and electronically controlled telescopic rods to realize automatic spraying of large wind power workpieces.
Through the automated spraying device, it is possible to remove surface impurities before spraying the workpiece, adjust the height of the spray gun and the distance of the workpiece, and adjust the placement status of the workpiece in real time to ensure uniform spraying on each side and improve the spray efficiency and effect.
Smart Images

Figure CN119793748A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of automated spraying, and in particular to an automated spraying device for large-scale wind power. Background Art
[0002] Spraying is a very important part of the manufacturing industry. Spraying is a process that uses a spray gun or a disc atomizer to apply a uniform and fine mist or powder coating to the surface of a workpiece with the help of pressure or centrifugal force. The equipment that realizes the spraying operation on the workpiece is called a lifting device. The lifting device used in industrial production can drive the spray gun to move to realize batch spraying operation or assembly line operation. The spraying device is a device that atomizes the spraying liquid and sprays it onto the spraying product, so that the surface of the spraying product is covered with the spraying liquid. It is a product of the development of industrial automation. With the increasing degree of automation, the application of spraying production lines is becoming more and more extensive. The existing spraying device usually includes a transport module for transporting products, a spraying mechanism for spraying products, and a drying box and other equipment required in the spraying process; The current technical status of spraying (spraying paint or zinc, etc.) large workpieces is that large workpieces (such as some wind turbine cabin components, which have irregular and complex shapes, and some workpieces also need to be sprayed on the inner cavity wall. The largest size is more than 5 meters at the widest point, and the weight of a single blank is about 50 tons) need to be manually sprayed by painters. Manual spraying is easy to affect human health, especially when spraying large wind power workpieces. Manual spraying cannot spray large wind power workpieces evenly. Therefore, it is necessary to design an automatic spraying device for large wind power. Summary of the invention
[0003] The purpose of the present invention is to provide an automatic spraying device for large-scale wind power to solve the problems raised in the above background technology.
[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: an automatic spraying device for large-scale wind power, comprising an operating frame; A controller, wherein the controller is fixedly mounted on a side wall of the operating frame; A fixing seat, the fixing seat is fixedly installed in front of the operating frame; A first piston rod is slidably connected to the interior of the fixing seat, a first cylinder is connected to the top of the first piston rod, and a fixing head is fixedly connected to the bottom of the first piston rod; A second fixing plate is fixedly installed in front of the fixing seat, a third piston rod is slidably connected to the inside of the second fixing plate, a third cylinder is connected to the top of the third piston rod, and an infrared imager is fixedly connected to the other end of the third piston rod; According to the above technical solution, a first fixing plate is fixedly installed on the side wall of the fixing seat, a second piston rod is slidably connected to the interior of the first fixing plate, a second cylinder is connected to the top of the second piston rod, the other end of the second piston rod is fixedly connected to a connecting frame, and the other end of the connecting frame is fixedly connected to a fan; According to the above technical solution, a first slide rail is fixedly installed on the top of the operating frame, a first slider is slidably installed on the track of the first slide rail, a second slide rail is fixedly connected to the side wall of the first slider, a sliding frame is fixedly connected to the other end of the second slide rail, a lead screw is slidably connected to the inside of the sliding frame, and both ends of the lead screw are rotatably connected to the support frame respectively; According to the above technical solution, a second slider is slidably installed on the track of the second slide rail, a groove is provided at the bottom end of the second slider, a rotating frame is rotatably connected inside the groove, an automatic spray gun is fixedly connected to the other end of the rotating frame, and a spray pipe is fixedly connected to the pipe end of the automatic spray gun; According to the above technical solution, a solenoid valve is fixedly installed on the pipe of the spray pipe, and a timer is fixedly connected to the top of the solenoid valve; According to the above technical solution, a support plate is fixedly installed on the top of the bottom plate of the operating frame, a driving motor is fixedly connected to the top of the support plate, an output end of the driving motor is connected to a driving gear, an outer end of the driving gear is rotatably connected to a conveyor belt, the other end of the conveyor belt is rotatably connected to a driven gear, and an inner part of the driven gear is connected to a rotating rod; According to the above technical solution, a rotating disk is provided on the outside of the rotating rod, a fixed rod is fixedly installed through the top of the rotating rod, one end of the fixed rod is fixedly connected to the first electrically controlled telescopic rod, and the other end of the fixed rod is fixedly connected to the third electrically controlled telescopic rod; The top of the rotating rod is fixedly connected to a second electrically-controlled telescopic rod, and the extended end of the second electrically-controlled telescopic rod is fixedly connected to a supporting seat; According to the above technical solution, a protective cover is also fixedly installed on the top of the bottom plate of the operating frame; According to the above technical solution, the method for using the automatic spraying device is characterized by comprising the following steps: S1, the operator places the workpiece on the support seat, starts the infrared imager, and inspects the surface of the workpiece; S2, adjusting the position of the automatic spray gun so that the muzzle of the automatic spray gun is aimed at the workpiece and spraying the workpiece; S3, adjusting the heights of the first electrically-controlled telescopic rod and the third electrically-controlled telescopic rod in real time according to the spraying conditions of the workpiece to ensure that each side of the workpiece is sprayed evenly.
[0005] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention, by providing an air cylinder, an infrared imager, a fan, a slide rail, an automatic spray gun and an electrically-controlled telescopic rod, can use the fan to blow away and remove impurities on the surface of the workpiece before spraying the workpiece, thereby improving the effect of spraying on the workpiece surface; by providing a first slide rail and a second slide rail, a rotating frame adjusts the height of the automatic spray gun and the distance from the workpiece, thereby improving the efficiency of workpiece spraying; by providing a first electrically-controlled telescopic rod and a third electrically-controlled telescopic rod, the placement state of the workpiece can be adjusted in real time, thereby ensuring that each side of the workpiece is sprayed evenly. BRIEF DESCRIPTION OF THE DRAWINGS
[0006] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the embodiments of the present invention, they are used to explain the present invention and do not constitute a limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of the overall front structure of the present invention; Figure 2 It is a schematic diagram of the enlarged structure of area A of the present invention; Figure 3 It is a schematic diagram of the overall side structure of the present invention; Figure 4 It is a schematic diagram of the overall internal structure of the present invention; Figure 5 It is a schematic diagram of the enlarged structure of region B of the present invention; Figure 6 is an enlarged structural schematic diagram of region C of the present invention; In the figure: 1, operating frame; 2, controller; 3, fixed seat; 4, first piston rod; 5, first cylinder; 6, first fixed plate; 7, second piston rod; 8, fan; 9, second cylinder; 10, fixed head; 11, second fixed plate; 12, third cylinder; 13, third piston rod; 14, infrared imager; 15, first slide rail; 16, first slider; 17, second slide rail; 18, support frame; 19, lead screw; 20, second slider; 21, rotating frame; 22, spray pipe; 23, solenoid valve; 24, timer; 25, protective cover; 26, driving motor; 27, driving gear; 28, conveyor belt; 29, driven gear; 30, rotating disk; 31, rotating rod; 32, fixed rod; 33, first electric telescopic rod; 34, second electric telescopic rod; 35, third electric telescopic rod; 36, support seat; 37, workpiece; 38, automatic spray gun. DETAILED DESCRIPTION
[0007] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.
[0008] See also Figure 1-6 , the present invention provides a technical solution: an automatic spraying device for large-scale wind power, comprising an operating frame 1, a controller 2 is fixedly installed on the side wall of the operating frame 1; A fixing seat 3 is fixedly installed in front of the operating frame 1, and a first piston rod 4 is slidably connected to the inside of the fixing seat 3, and a first cylinder 5 is connected to the top of the first piston rod 4, and the first cylinder 5 is externally connected to an engine, and the engine is externally connected to a power source, and the power source starts the engine to control the first cylinder 5 to drive the piston rod 4 to perform linear motion, and a fixing head 10 is fixedly connected to the bottom of the first piston rod 4, and the fixing head 10 plays a fixing role; A first fixing plate 6 is fixedly installed on the side wall of the fixing seat 3, a second piston rod 7 is slidably connected to the inside of the first fixing plate 6, a second cylinder 9 is connected to the top of the second piston rod 7, the second cylinder 9 is used to control the second piston rod 7 to move up and down, the other end of the second piston rod 7 is fixedly connected to a connecting frame, the other end of the connecting frame is fixedly connected to a fan 8, the outside of the fan 8 is connected to a power supply, the power supply controls the rotation of the fan 8, and the fan 8 plays a role in dust removal; A second fixing plate 11 is fixedly installed in front of the fixing seat 3, and a third piston rod 13 is slidably connected to the inside of the second fixing plate 11, and a third cylinder 12 is connected to the top of the third piston rod 13, and the third cylinder 12 is used to control the up and down movement of the third piston rod 13. The other end of the third piston rod 13 is fixedly connected to an infrared imager 14, and the infrared imager 14 receives the infrared radiation energy of the target through an optical imaging system, and then acts on the photosensitive element of the infrared detector, and obtains an infrared thermal image through subsequent circuits and signal processing. The infrared imager 14 is used to photograph and image the surface of the sprayed part; A first slide rail 15 is fixedly installed on the top of the operating frame 1, a first slider 16 is slidably installed on the track of the first slide rail 15, a second slide rail 17 is fixedly connected to the side wall of the first slider 16, the other end of the second slide rail 17 is fixedly connected to the sliding frame, the inside of the sliding frame is slidably connected to a lead screw 19, the top of the lead screw 19 is connected to a motor, the motor is externally connected to a power supply, the power supply starts the motor to drive the lead screw 19 to rotate together, the two ends of the lead screw 19 are respectively rotatably connected to a support frame 18, and a second slider 20 is slidably installed on the track of the second slide rail 17 The bottom end of the second slider 20 is provided with a groove, and a rotating frame 21 is rotatably connected inside the groove. One end of the rotating frame 21 connected to the groove is connected to a motor, and the outside of the motor is connected to a power supply. The power supply controls the motor and the rotating frame 21 to rotate inside the groove together. The other end of the rotating frame 21 is fixedly connected to an automatic spray gun 38. The automatic spray gun 38 uses a high-speed airflow to make the spray gun partially vacuum, thereby generating suction to suck the paint from the tube to the nozzle for atomization spraying. The pipe end of the automatic spray gun 38 is fixedly connected to a spray pipe 22, and the spray pipe 22 is used to transmit the paint; A solenoid valve 23 is fixedly installed on the pipe of the spray pipe 22. The solenoid valve 23 is externally connected to a power source. The power source controls the switch of the solenoid valve 23. The solenoid valve 23 is used to control the flow of the paint inside the spray pipe 22. A timer 24 is fixedly connected to the top of the solenoid valve 23. The timer 24 plays a role in measuring time. A support plate is fixedly installed on the top of the bottom plate of the operating frame 1, and a driving motor 26 is fixedly connected to the top of the supporting plate. The driving motor 26 is externally connected to a power source, and the power source starts the driving motor 26. The output end of the driving motor 26 is connected to a driving gear 27, and the driving gear 27 is externally rotatably connected to a conveyor belt 28, and the other end of the conveyor belt 28 is rotatably connected to a driven gear 29, and the driven gear 29 is internally connected to a rotating rod 31. The driving motor 26 drives the driving gear 27 to rotate together, and the driving gear 27 drives the conveyor belt 28 and the driven gear 29 to rotate together, and the rotating rod 31 rotates accordingly; A rotating disk 30 is provided on the outside of the rotating rod 31, and a fixed rod 32 is fixedly installed on the top of the rotating rod 31, one end of the fixed rod 32 is fixedly connected to a first electrically-controlled telescopic rod 33, and the other end of the fixed rod 32 is fixedly connected to a third electrically-controlled telescopic rod 35, the first electrically-controlled telescopic rod 33 and the third electrically-controlled telescopic rod 35 are respectively connected to power sources on the outside, and the power source controls the first electrically-controlled telescopic rod 33 and the third electrically-controlled telescopic rod 35 to be extended and retracted, and the extended ends of the first electrically-controlled telescopic rod 33 and the third electrically-controlled telescopic rod 35 are connected to a workpiece 37, and the first electrically-controlled telescopic rod 33 and the third electrically-controlled telescopic rod 35 are used to control the height of the left and right ends of the workpiece 37, and a second electrically-controlled telescopic rod 34 is fixedly connected to the top of the rotating rod 31, and the second electrically-controlled telescopic rod 34 is connected to a power source on the outside, and the power source controls the extension and retraction of the second electrically-controlled telescopic rod 34, and the extended end of the second electrically-controlled telescopic rod 34 is fixedly connected to a support seat 36, and the support seat 36 is in the shape of the letter V, and the support seat 36 plays a role in supporting the workpiece; A protective cover 25 is also fixedly mounted on the top of the bottom plate of the operating frame 1. The protective cover 25 is used to protect the driving motor 26, so that the paint does not splash during the spraying process to cause structural damage, thereby increasing the service life of the operating frame 1; In this embodiment, the method of using the operating frame 1 is as follows: S1, the operator places the workpiece 37 on the support seat 36, starts the infrared imager 14, and detects the surface of the workpiece 37; Specifically, after the workpiece 37 is stably placed above the support seat 36, the operator starts the first air cylinder 5, which controls the first piston rod 7 to move downward, and the first piston rod 7 drives the fixed head 10 to move downward together, until the fixed head 10 moves down to the top of the workpiece 37 and stops, and the fixed head 10 and the support seat 36 fix the workpiece 37 together, and then the third air cylinder 12 is started, and the third cylinder 12 controls the third piston rod 13 to move downward, and the third piston rod 13 drives the infrared imager 14 to move downward, and stops when the infrared imager 14 is located above the workpiece 37, and then the infrared imager 14 is started to shoot and image the surface of the workpiece 37, and the qualified surface image of the workpiece 37 to be sprayed is set to be flawless; When the surface image of the workpiece 37 captured by the infrared imager 14 shows a number of black spots, indicating that there are a number of impurities on the surface of the workpiece 37, the operator starts the second cylinder 9, and the second cylinder 9 drives the second piston rod 7 and the fan 8 to move downward until the fan 8 is located above the workpiece 37 and stops, and starts the fan 8 to remove impurities from the surface of the workpiece 37. The power of the fan 8 is set to high speed and low speed. When the impurity content of the surface image of the workpiece 37 exceeds one third, the speed of the fan 8 is controlled to be high speed. When the impurity content of the surface image of the workpiece 37 is less than one third, the speed of the fan 8 is controlled to be low speed until the surface of the workpiece 37 is free of impurities and stops; S2, adjusting the position of the automatic spray gun 38 so that the muzzle of the automatic spray gun 38 is aimed at the workpiece 37, and spraying the workpiece 37; Specifically, according to the placement height of the workpiece 37, the operator adjusts the height of the automatic spray gun 38, starts the motor connected to the top of the lead screw 19, the motor drives the lead screw 19 to rotate together, the rotation of the lead screw 19 drives the sliding frame to move, and the sliding frame drives the second slide rail 17 to move downward on the track of the first slide rail 15, and the automatic spray gun 38 stops moving when it is located obliquely above the workpiece 37. At this time, the nozzle of the automatic spray gun 38 is aimed at the upper surface of the workpiece 37, and the operator starts the solenoid valve 23 and the timer 24. The spray material is transported to the automatic spray gun 38 through the spray pipe 22, and the automatic spray gun 38 sprays the workpiece 37. The spraying time of the upper surface of the standard workpiece is set to T. When the spraying time reaches T, the solenoid valve 23 is automatically closed, and the infrared imager 14 is started at this time to capture and image the surface of the workpiece 37 after spraying, and the surface of the workpiece 37 is set to be displayed as a surface without black spots after the surface spraying is qualified; When the surface of the workpiece 37 is imaged as a surface without black spots, the operator adjusts the position of the automatic spray gun 38, controls the automatic spray gun 38 to continue to move downward, rotates the rotating frame 21 to drive the nozzle of the automatic spray gun 38 to move upward, and enables the automatic spray gun 38 to spray the lower surface of the workpiece 37; When the surface imaging of the workpiece 37 shows that there are black spots, the surface spraying is uneven, and the automatic spray gun 38 is started to continue spraying the black spots until the surface spraying of the workpiece 37 is qualified; S3, adjusting the heights of the first electrically-controlled telescopic rod 33 and the third electrically-controlled telescopic rod 35 in real time according to the spraying condition of the workpiece 37 to ensure that each side of the workpiece 37 is sprayed evenly.
[0009] Since the spraying on the lower surface of the workpiece 37 cannot be captured by the infrared imager 14, the placement direction of the workpiece 37 needs to be adjusted. After the automatic spray gun 38 sprays the lower surface of the workpiece 37 for a period of time, the first electrically-controlled telescopic rod 33 is started to retract, and the workpiece 37 is controlled to be higher on the left and lower on the right. The automatic spray gun 38 continues to spray the lower surface of the workpiece 37, so as to ensure that the lower surface of the workpiece 37 is sprayed evenly.
[0010] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.
[0011] Finally, it should be noted that the above description is only 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 aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. An automatic spraying device for large-scale wind power, characterized in that: include: Operating frame (1); A controller (2), wherein the controller (2) is fixedly mounted on a side wall of the operating frame (1); A fixed seat (3), wherein the fixed seat (3) is fixedly mounted in front of the operating frame (1); A first piston rod (4) is slidably connected to the interior of the fixing seat (3), the top of the first piston rod (4) is connected to a first cylinder (5), and the bottom of the first piston rod (4) is fixedly connected to a fixing head (10); A second fixing plate (11) is fixedly mounted in front of the fixing seat (3); a third piston rod (13) is slidably connected to the interior of the second fixing plate (11); the top of the third piston rod (13) is connected to a third cylinder (12); and the other end of the third piston rod (13) is fixedly connected to an infrared imager (14).
2. The automatic spraying device for large-scale wind power according to claim 1 is characterized in that: A first fixing plate (6) is fixedly mounted on the side wall of the fixing seat (3); a second piston rod (7) is slidably connected to the interior of the first fixing plate (6); a second cylinder (9) is connected to the top of the second piston rod (7); the other end of the second piston rod (7) is fixedly connected to a connecting frame; and the other end of the connecting frame is fixedly connected to a fan (8).
3. The automatic spraying device for large-scale wind power according to claim 1 is characterized in that: A first slide rail (15) is fixedly mounted on the top of the operating frame (1), a first slider (16) is slidably mounted on the track of the first slide rail (15), a second slide rail (17) is fixedly connected to the side wall of the first slider (16), the other end of the second slide rail (17) is fixedly connected to a sliding frame, a lead screw (19) is slidably connected inside the sliding frame, and both ends of the lead screw (19) are rotatably connected to support frames (18).
4. The automatic spraying device for large-scale wind power according to claim 3 is characterized in that: A second sliding block (20) is slidably mounted on the track of the second slide rail (17); a groove is provided at the bottom end of the second sliding block (20); a rotating frame (21) is rotatably connected inside the groove; an automatic spray gun (38) is fixedly connected to the other end of the rotating frame (21); and a spray pipe (22) is fixedly connected to the pipe end of the automatic spray gun (38).
5. The automatic spraying device for large-scale wind power according to claim 4 is characterized in that: A solenoid valve (23) is fixedly mounted on the spray pipe (22), and a timer (24) is fixedly connected to the top of the solenoid valve (23).
6. The automatic spraying device for large-scale wind power according to claim 1 is characterized in that: A support plate is fixedly mounted on the top of the bottom plate of the operating frame (1); a driving motor (26) is fixedly connected to the top of the support plate; an output end of the driving motor (26) is connected to a driving gear (27); an outer end of the driving gear (27) is rotatably connected to a conveyor belt (28); the other end of the conveyor belt (28) is rotatably connected to a driven gear (29); and an inner end of the driven gear (29) is connected to a rotating rod (31).
7. The automatic spraying device for large-scale wind power according to claim 6, characterized in that: A rotating disk (30) is provided on the outside of the rotating rod (31); a fixing rod (32) is fixedly installed through the top end of the rotating rod (31); one end of the fixing rod (32) is fixedly connected to a first electrically controlled telescopic rod (33); and the other end of the fixing rod (32) is fixedly connected to a third electrically controlled telescopic rod (35); The top of the rotating rod (31) is fixedly connected to a second electrically-controlled telescopic rod (34), and the extended end of the second electrically-controlled telescopic rod (34) is fixedly connected to a support seat (36).
8. The automatic spraying device for large-scale wind power according to claim 1 is characterized in that: A protective cover (25) is also fixedly mounted on the top of the bottom plate of the operating frame (1).
9. The method for using the automatic spraying device for large-scale wind power according to claim 8, characterized in that: The following steps are involved: S1, the operator places the workpiece (37) on the support seat (36), starts the infrared imager (14), and detects the surface of the workpiece (37); S2, adjusting the position of the automatic spray gun (38) so that the muzzle of the automatic spray gun (38) is aimed at the workpiece (37), and spraying the workpiece (37); S3, adjusting the heights of the first electrically controlled telescopic rod (33) and the third electrically controlled telescopic rod (35) in real time according to the spraying condition of the workpiece (37), so as to ensure that each side of the workpiece (37) is sprayed evenly.
10. The method for using the automatic spraying device for large-scale wind power according to claim 9, characterized in that: The specific operation steps of the above step S2 are as follows: Specifically, according to the placement height of the workpiece (37), the operator adjusts the height of the automatic spray gun (38), starts the motor connected to the top of the lead screw (19), and the motor drives the lead screw (19) to rotate together. The rotation of the lead screw (19) drives the sliding frame to move, and the sliding frame drives the second slide rail (17) to move downward on the track of the first slide rail (15). When the automatic spray gun (38) is located obliquely above the workpiece (37), it stops moving. At this time, the nozzle of the automatic spray gun (38) is aimed at the workpiece (37). The operator starts the electromagnetic valve (23) and the timer (24), and the spray material is transported to the automatic spray gun (38) through the spray pipe (22). The automatic spray gun (38) sprays the workpiece (37). The spraying time of the upper surface of the standard workpiece is set to T. When the spraying time reaches T, the electromagnetic valve (23) is automatically closed. At this time, the infrared imager (14) is started to take an image of the surface of the workpiece (37) after spraying. The surface of the workpiece (37) is set to be displayed as a surface without black spots after the surface is sprayed. When the surface of the workpiece (37) is imaged as a surface without black spots, the operator adjusts the position of the automatic spray gun (38), controls the automatic spray gun (38) to continue to move downward, rotates the rotating frame (21) to drive the nozzle of the automatic spray gun (38) to move upward, and causes the automatic spray gun (38) to spray the lower surface of the workpiece (37); When the surface imaging of the workpiece (37) shows that it contains black spots, the surface spraying is uneven. At this time, the automatic spray gun (38) is started to continue spraying the black spot part until the surface spraying of the workpiece (37) is qualified.