A spraying apparatus and spraying method for coating large machine tool castings.

Abstract

This invention relates to the field of coating spraying for machine tool castings, and provides a spraying device and method for coating large machine tool castings. The device includes: a base plate on which a conveying unit for conveying the casting body is mounted; a spraying robotic arm on which a spraying unit for spraying the casting body is mounted; the spraying unit includes: a spraying pump; a storage tank connected to a connecting box, the connecting box containing different spraying materials; a spraying box; a spraying head fixedly connected to the spraying box; and a cleaning unit on the outside of the spraying head for cleaning the inside of the spraying head, the cleaning unit including: a scraping unit. This application achieves the recovery of scraped materials and the rinsing and cleaning of the spraying head through the switching control of a first valve and a second valve. In conjunction with the filter layer in the first box, the recovered materials can be filtered and purified, achieving recycling, which not only reduces material waste but also reduces waste emissions.

Description

Technical Field

[0001] This invention belongs to the technical field of coating spraying for machine tool castings, and particularly relates to a spraying device and spraying method for coating large machine tool castings. Background Technology

[0002] To extend the service life of large machine tool castings and improve their corrosion and wear resistance, coating spraying is a key process in their manufacturing. Currently, the industry commonly uses seven-axis spraying robots in conjunction with spraying equipment to complete the work, adapting to the complex shapes and structures of the castings and ensuring uniform coating. Meanwhile, six-axis robots, with their flexible multi-dimensional motion characteristics, high-precision positioning capabilities, and stable operating efficiency, are also increasingly being applied to the coating of large machine tool castings, especially suitable for spraying complex curved surfaces and irregularly shaped structures of medium to large castings. However, existing spraying equipment and methods, whether paired with seven-axis robots or six-axis robots, have significant technical shortcomings: for the multi-layer coating requirements often needed for large machine tool castings, existing equipment generally uses a single nozzle to spray multiple coating materials. Due to the differences in chemical composition and physical properties of different coating materials, cross-mixing easily occurs within a single nozzle, leading to chemical reactions, precipitation, and other adverse phenomena. This not only damages the coating performance but can also cause nozzle blockage, resulting in interrupted spraying operations.

[0003] Furthermore, large machine tool castings are bulky and heavy, with some having complex structures such as deep cavities, corners, and uneven surfaces. While six-axis robots offer the advantage of multi-degree-of-freedom motion, existing spraying devices are not well-suited to them. The connection stability between the spraying unit and the robot arm is poor, leading to wobbling during high-speed spraying operations and affecting spraying accuracy. Simultaneously, the lack of coordinated control between the six-axis robot's motion trajectory and spraying rhythm makes it difficult to dynamically adapt to the spraying requirements of different parts of the casting (e.g., slowing down and increasing the spray volume in deep cavities, while speeding up and uniformly spraying in flat areas), further reducing spraying quality. These issues not only increase equipment maintenance costs and reduce production efficiency but also affect the casting pass rate due to spraying interruptions or coating defects, making it difficult to meet the high-precision, high-efficiency spraying requirements of large machine tool castings. Therefore, this paper proposes a spraying device and method for coating large machine tool castings that can solve the above problems and is highly compatible with six-axis robots. Summary of the Invention

[0004] This invention provides a spraying device and method for coating large machine tool castings, aiming to address significant technical deficiencies in existing spraying devices and methods. For the multi-layer coating requirements often present in large machine tool castings, existing devices generally use a single nozzle to apply multiple coating materials. Due to differences in the chemical composition and physical properties of different coating materials, cross-mixing easily occurs within a single nozzle, leading to chemical reactions, precipitation, and other adverse phenomena. This not only damages coating performance but can also cause nozzle blockage, resulting in spraying interruptions. This problem not only increases equipment maintenance costs and reduces production efficiency but also affects the casting pass rate due to spraying interruptions or coating quality defects, making it difficult to meet the high-precision, high-efficiency spraying requirements of large machine tool castings.

[0005] This invention is implemented as follows: a spraying device for coating large machine tool castings includes: a base plate on which a conveying unit for conveying the casting body is mounted; a spraying robotic arm mounted on the base plate, on which a spraying unit for spraying the casting body is mounted; the spraying unit includes: a spraying pump connected to a storage tank via a connecting pipe; the storage tank connected to a connecting box; the connecting box connected to the spraying robotic arm; different spraying materials stored inside the connecting box; a spraying box connected to the connecting box via a connecting pipe; a spraying head fixedly connected to the spraying box; a cleaning unit for cleaning the inside of the spraying head located outside the spraying head; the cleaning unit includes: a scraping unit located inside the spraying box for scraping off the spraying material adhering to the inner wall of the spraying box; and a circulation unit for providing power to the scraping unit.

[0006] Preferably, the conveying unit includes a conveying plate, which is connected to the base plate via a guide rail, and a rotating plate is rotatably connected to the conveying plate.

[0007] Preferably, the circulation unit includes a first connecting pipe, a second connecting pipe fixedly connected to the side of the first connecting pipe, the second connecting pipe being connected to a first valve, a first connecting rod fixedly connected to the side of the first connecting pipe, a second valve fixedly connected to the end of the first connecting rod, the first connecting pipe being fixedly connected to a third connecting pipe, a fourth connecting pipe rotatably connected to the third connecting pipe, a cover plate provided on the fourth connecting pipe to cooperate with the spray head, a first housing fixedly connected to the side of the spray box, and the first housing being connected to the first valve and the second valve respectively via connecting hoses.

[0008] Preferably, the scraping unit includes a first rotating shaft rotatably connected to the spray box body, a plurality of first scrapers arranged in a circumferential array are fixedly connected to the side of the first rotating shaft, a second scraper is inserted into the first scraper, and a scraping pad is fixedly connected to the end of the second scraper.

[0009] Preferably, the first scraper has a slot, the second scraper is inserted into the first scraper, a guide plate is fixedly connected to the side of the second scraper, the slot has a snap-fit ​​groove, a guide rod is fixedly connected in the snap-fit ​​groove, the guide rod passes through the guide plate, and the guide plate is connected to the inner wall of the snap-fit ​​groove by a spring for providing elasticity.

[0010] Preferably, the side of the first rotating shaft is rotatably connected to a plurality of rotating blades arranged in a circular array via a second rotating shaft, a torsion spring is provided on the outer side of the second rotating shaft, and a limiting plate for limiting the position of the rotating blades is fixedly connected to the second rotating shaft.

[0011] Preferably, a filter layer is fixedly connected inside the first box.

[0012] A spraying method for coating large machine tool castings, comprising the following steps: Step 1: Loading and Positioning. Place the large machine tool casting to be painted on the rotating plate and fix it with positioning fixtures to ensure that the casting does not shift during the painting process; drive the servo motor of the conveying unit to move the conveying plate along the guide rail to the painting station, at which point the painting robot arm is in the initial standby state.

[0013] Step 2: Setting spraying parameters. Based on the coating requirements of the casting, the motion trajectory of the spraying robot arm, spraying speed, working pressure of each spraying pump, and spraying time are set through the control system; at the same time, the working parameters of the cleaning unit are set, such as the rotation speed of the scraping unit and the duration of the cleaning operation.

[0014] Step 3: First Coating Application. Start the spray pump and solenoid valve corresponding to the first coating layer. The spraying robotic arm moves along the set trajectory, and the spray head evenly sprays the first coating material onto the casting surface. During the spraying process, according to the casting's shape requirements, a stepper motor drives a rotating plate to adjust the casting's posture, ensuring that all parts of the casting are fully coated. After spraying is complete, turn off the spray pump and solenoid valve.

[0015] Step 4: Cleaning Operation. Start the cleaning unit, drive the motor to rotate the first shaft, and the scraping unit scrapes off the first layer of coating material adhering to the inner wall of the spray box; at the same time, open the first valve, and the scraped material debris enters the first box for filtration with the airflow. The filtered material is then recycled to the recovery chamber connected to the box; then rotate the fourth connecting pipe to close the cover plate at the spray head outlet, close the first valve, open the second valve, start the circulation pump, and use the cleaning liquid in the first box to rinse the inside of the spray head. After rinsing, close the second valve and the circulation pump, and open the cover plate to reset it.

[0016] Step 5: Subsequent Coating Spraying. Repeat steps 3-4 to complete the spraying and cleaning of the second, third, and subsequent coatings in sequence until all coatings are sprayed. After each coating is sprayed, perform a cleaning operation to avoid mixing of different coating materials in the spraying system.

[0017] Step Six: Material Unloading Completed. After all coatings are applied, the conveyor plate is moved to the unloading station via the conveyor unit. The positioning fixtures are removed, and the coated castings are taken out for subsequent coating curing treatment. At the same time, the equipment is thoroughly cleaned to ensure that there is no material residue in the coating system, preparing for the coating of the next batch of castings.

[0018] Compared with existing technologies, 1. By connecting the box body to multiple independent storage chambers, combined with the scraping and rinsing functions of the cleaning unit, the problem of cross-mixing of different coating materials is completely solved, avoiding nozzle clogging and coating performance damage, reducing equipment maintenance costs, and improving production efficiency; 2. Using a six-axis robot as the spraying robotic arm, its multi-degree-of-freedom motion characteristics and high-precision positioning capabilities enable coordinated linkage with the spraying and conveying units, accurately adapting to the complex shape structure of large machine tool castings, eliminating spraying blind spots, and improving spraying uniformity and accuracy; 3. The coordinated control of the six-axis robot with the cleaning and circulation units realizes automated continuous operation of spraying, cleaning, and material recovery, reducing manual intervention and further improving production efficiency; 4. Through the switching control of the first and second valves, the recovery of scraped material and the rinsing and cleaning of the spray head are realized. Combined with the filter layer in the first box body, the recovered material can be filtered and purified, realizing recycling, which not only reduces material waste but also reduces waste emissions; 5. The lightweight adaptation design of the six-axis robot (such as using lightweight materials for the connecting housing and small drive motors for the scraping unit) reduces the robot's load, improves the robot's operational stability and service life, and further ensures the continuity and reliability of the spraying operation. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of a spraying device for coating large machine tool castings provided by the present invention. Figure 1 ; Figure 2 yes Figure 1 Enlarged structural diagram at point A; Figure 3 This is a partial structural schematic diagram of a spraying device for coating large machine tool castings provided by the present invention; Figure 4 This is a schematic diagram of the overall structure of a spraying device for coating large machine tool castings provided by the present invention. Figure 2 ; Figure 5 yes Figure 4 Enlarged structural diagram at point B; Figure 6 This is a schematic diagram of the internal structure of the spraying box in a spraying device for coating spraying large machine tool castings provided by the present invention; Figure 7 This is a schematic diagram of the rotating blades in a spraying device for coating large machine tool castings provided by the present invention; Figure 8 This is a cross-sectional view of the connection between the first scraper and the second scraper in a spraying device for coating spraying large machine tool castings provided by the present invention. Figure 9 This is a cross-sectional structural diagram of the first housing in a spraying device for coating large machine tool castings provided by the present invention.

[0020] Figure reference numerals: 1. Base plate; 2. Spraying robot arm; 3. Spraying pump; 4. Connecting rigid pipe; 5. Storage tank; 6. Spraying box; 7. Connecting box; 8. Spray head; 9. Conveyor plate; 10. Guide rail; 11. Rotating plate; 12. First connecting pipe; 13. Second connecting pipe; 14. First valve; 15. First connecting rod; 16. Second valve; 17. Third connecting pipe; 18. Fourth connecting pipe; 19. Cover plate; 20. First box; 21. Connecting hose; 22. First rotating shaft; 23. First scraper; 24. Second scraper; 25. Scraping pad; 26. Slot; 27. Guide plate; 28. Snap-fit ​​groove; 29. ​​Guide rod; 30. Spring; 31. Second rotating shaft; 32. Rotating blade; 33. Torsion spring; 34. Limiting plate; 35. Filter layer. Detailed Implementation

[0021] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein in the specification of the application is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having," and any variations thereof, in the specification, claims, and foregoing drawings of this application are intended to cover non-exclusive inclusion. The terms "first," "second," etc., in the specification, claims, or foregoing drawings of this application are used to distinguish different objects, not to describe a particular order.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] This invention provides a spraying device for coating large machine tool castings, such as... Figures 1-9As shown, firstly, a flat installation site is selected, and the base plate 1 is fixed horizontally. The base plate 1 is made of high-strength alloy material to ensure the stability of the device during operation and avoid the impact of vibration on the spraying accuracy. It includes: the base plate 1, on which a conveying unit for conveying the main body of the casting is installed; the spraying robotic arm 2, which is a six-axis industrial robot. This six-axis robot has six degrees of freedom of movement, and can realize translational movement in the forward, backward, left, right, and up and down directions, as well as rotational movement around three coordinate axes. It has a wide range of motion, high flexibility, and a positioning accuracy of ±0.02mm. It can accurately adapt to the complex shape structure and irregular curved surface spraying requirements of large machine tool castings (such as bed and column). It is fixedly installed on one side of the base plate 1. The end effector of the six-axis robot is detachably connected to the connecting box 7 by high-strength bolts. The connection part is equipped with anti-loosening gaskets and positioning pins to ensure stable connection during the spraying operation, without shaking or displacement, and to avoid the impact of loose connection on the spraying accuracy; it is equipped with a conveying unit for conveying the main body of the casting. The coating unit for spraying the coating body includes: a coating pump 3, which is connected to a storage tank 5 via a connecting rigid pipe 4. The storage tank 5 is connected to a connecting box 7, which is fixedly connected to the end effector of the six-axis robot. The connecting box 7 is made of lightweight aluminum alloy to reduce the load on the six-axis robot and avoid affecting the robot's motion accuracy and service life due to excessive load. The connecting box 7 has multiple independent storage chambers, each corresponding to a type of coating material. Sealed partitions are set between the chambers to ensure that different materials do not mix. The coating box 6 is connected to the connecting box 7 via a connecting rigid pipe 4. A spray head 8 is fixedly connected to the coating box 6. A cleaning unit for cleaning the inside of the spray head 8 is set on the outside of the spray head 8. The cleaning unit includes: a scraping unit, which is set inside the coating box 6, for scraping off the coating material adhering to the inner wall of the coating box 6; and a circulation unit, which provides power for the scraping unit.

[0024] After the device is assembled, initial debugging is performed: check the sealing of each connection part to ensure that there is no raw material leakage; calibrate the initial position of the spray head 8 through the control system of the spraying robot arm 2; debug the conveying unit to ensure that the conveying plate 9 slides smoothly along the guide rail 10 and the rotating plate 11 rotates flexibly; conduct a no-load test run on the cleaning unit to verify whether the scraping unit action is continuous and whether the pressure of the circulation unit is stable.

[0025] The conveying unit includes a conveying plate 9, which is connected to the base plate 1 via a guide rail 10. A rotating plate 11 is rotatably connected to the conveying plate 9. The rotating plate 11 is driven by a stepper motor, which is fixed inside the conveying plate 9. Its output shaft meshes with the gear ring at the bottom of the rotating plate 11 via a gear set. By controlling the rotation angle of the stepper motor, the rotating plate 11 can be driven to rotate at any angle, thereby driving the casting to rotate and ensuring that all surfaces of the casting can be uniformly sprayed, which is suitable for the spraying requirements of complex shapes of large machine tool castings in the background technology.

[0026] The circulation unit includes a first connecting pipe 12, a second connecting pipe 13 fixedly connected to the side of the first connecting pipe 12, the second connecting pipe 13 connected to a first valve 14, a first connecting rod 15 fixedly connected to the side of the first connecting pipe 12, a second valve 16 fixedly connected to the end of the first connecting rod 15, a third connecting pipe 17 fixedly connected to the first connecting pipe 12, a fourth connecting pipe 18 rotatably connected to the third connecting pipe 17, a cover plate 19 for cooperating with the spray head 8 provided on the fourth connecting pipe 18, and a first box 20 fixedly connected to the side of the spray box 6. The first box 20 is connected via a connecting... The connecting hose 21 is connected to the first valve 14 and the second valve 16 respectively. The first valve 14 and the second valve 16 are electromagnetic reversing valves. When a certain coating needs to be sprayed, the control system controls the spraying pump 3 of the corresponding storage chamber to start, and at the same time opens the corresponding electromagnetic reversing valve. The raw material enters the spraying box 6 through the connecting hard pipe 4, and is then sprayed out by the corresponding spraying head 8. When changing the coating, the current spraying pump 3 and electromagnetic reversing valve are turned off, the cleaning unit is started to clean the spraying box 6 and the spraying head 8, and then the spraying pump 3 and electromagnetic reversing valve corresponding to the next coating are started to realize the switching spraying of different coatings.

[0027] The scraping unit includes a first rotating shaft 22 rotatably connected inside the spray box 6. Multiple first scrapers 23 arranged in a circular array are fixedly connected to the side of the first rotating shaft 22. A second scraper 24 is inserted into the first scraper 23. A scraping pad 25 is fixedly connected to the end of the second scraper 24.

[0028] The first scraper 23 has a slot 26, and the second scraper 24 is inserted into the first scraper 23. A guide plate 27 is fixedly connected to the side of the second scraper 24. A snap-fit ​​groove 28 is opened on the slot 26, and a guide rod 29 is fixedly connected in the snap-fit ​​groove 28. The guide rod 29 passes through the guide plate 27. The guide plate 27 is connected to the inner wall of the snap-fit ​​groove 28 through a spring 30 to provide elasticity. Under the elastic force of the spring 30, the scraping pad 25 is always in close contact with the inner wall of the spray box 6. When the first rotating shaft 22 rotates, it drives the first scraper 23 and the second scraper 24 to rotate synchronously. The scraping pad 25 scrapes off the coating material adhering to the inner wall of the spray box 6. When encountering protrusions or irregular parts of the inner wall of the spray box 6, the second scraper 24 can slide along the slot 26 to compress the spring 30, avoiding excessive friction between the scraping pad 25 and the inner wall and ensuring thorough scraping.

[0029] The side of the first rotating shaft 22 is rotatably connected to a plurality of rotating blades 32 arranged in a circular array via a second rotating shaft 31. A torsion spring 33 is provided on the outer side of the second rotating shaft 31. A limiting plate 34 for limiting the position of the rotating blades 32 is fixedly connected to the second rotating shaft 31. When the scraping unit is working, the rotation of the first rotating shaft 22 drives the rotating blades 32 to rotate synchronously. The rotating blades 32 unfold under the action of centrifugal force, causing disturbance to the air in the spray box 6 and forming an airflow, which helps to blow the scraped material debris toward the feed port of the circulation unit. When the work stops, under the elastic force of the torsion spring 33, the rotating blades 32 return to their original position and adhere to the first rotating shaft 22, without affecting the flow of material inside the spray box 6.

[0030] During cleaning operations, the drive motor is started to rotate the first rotating shaft 22, and the scraping unit begins to scrape off the adhering material on the inner wall of the spray box 6. At the same time, the first valve 14 is opened and the second valve 16 is closed. Under the air pressure inside the spray box 6, the scraped material debris is carried by the airflow through the first connecting pipe 12, the second connecting pipe 13, and the connecting hose 21 into the first box 20. After being filtered by the filter layer 35, the pure material enters the recycling chamber for recycling. When it is necessary to clean the spray head 8, the fourth connecting pipe 18 is rotated so that the cover plate 19 is closed at the outlet of the spray head 8, the first valve 14 is closed, the second valve 16 is opened, and the circulation pump is started to transport the cleaning liquid in the first box 20 to the spray box 6 through the connecting hose 21, the second valve 16, and the first connecting pipe 12 to rinse the inside of the spray head 8. The waste liquid after rinsing is then returned to the first box 20 for filtration through the first connecting pipe 12, realizing the recycling of the cleaning liquid.

[0031] The first housing 20 has a filter layer 35 fixedly connected inside.

[0032] A spraying method for coating large machine tool castings, comprising the following steps: Step 1: Loading and Positioning. Place the large machine tool casting to be painted (such as a bed casting, weighing 5-10 tons) on the rotating plate 11. Secure the casting with a hydraulic positioning fixture. A buffer pad is placed at the contact point between the positioning fixture and the casting to prevent damage to the casting surface and ensure the casting does not shift during painting. Driven by the servo motor of the conveying unit, move the conveyor plate 9 along the guide rail 10 to the painting station. At this point, the six-axis robot is in its initial standby state. The control system calibrates the position of the six-axis robot's end effector to ensure the initial distance between the painting head 8 and the casting is approximately 180mm. Simultaneously, complete the linkage debugging of the six-axis robot with the conveying unit and the cleaning unit to ensure coordinated movement of all components without jamming or interference.

[0033] Step Two: Setting Spraying Parameters. Based on the coating requirements of the casting (e.g., coating thickness of 0.3-0.5mm, 3 layers in total: the first layer is an anti-rust primer, the second layer is a transition layer, and the third layer is a wear-resistant topcoat), the motion trajectory of the six-axis robot is set through the control system. The 3D model of the casting is pre-entered using a teaching mode to generate the optimal spraying trajectory, avoiding repeated spraying or omissions. The spraying speed is set to 50-80mm / s. Differential parameters are set based on the structural characteristics of different parts of the casting: 50mm / s for deep cavities and 0.3MPa for spraying pressure; 80mm / s for flat surfaces and 0.2MPa for spraying pressure. Simultaneously, the working pressure and spraying time of each spraying pump 3, as well as the working parameters of the cleaning unit, are set, such as a scraping unit rotation speed of 150r / min and a cleaning operation duration of 30s, ensuring precise coordination between the six-axis robot's movements and the spraying and cleaning operations.

[0034] Step 3: First Coating Application. Start the spray pump 3 and solenoid valve corresponding to the first coating layer (rust-preventive primer). The six-axis robot moves along the set trajectory, driving the spray head 8 to move via the end effector, evenly spraying the rust-preventive primer onto the casting surface. During the spraying process, according to the casting's shape requirements, the rotating plate 11 is driven to rotate via a stepper motor. Simultaneously, the six-axis robot adjusts its own posture (e.g., rotating around the Z-axis, adjusting the end effector angle) to ensure thorough spraying of all parts of the casting (including deep cavities, corners, and irregular curved surfaces), avoiding blind spots. After spraying is complete, shut off the spray pump 3 and solenoid valve. The six-axis robot then moves the spraying unit to the preset cleaning station, ready for cleaning operations.

[0035] Step 4: Cleaning Operation. Start the cleaning unit, drive the motor to rotate the first rotating shaft 22, and the scraping unit scrapes off the anti-rust primer adhering to the inner wall of the spraying chamber 6. Simultaneously, open the first valve 14, and the scraped primer debris enters the first chamber 20 for filtration with the airflow. The filtered primer is then recycled to the recovery chamber connected to the chamber 7. Next, rotate the fourth connecting pipe 18 to cover the outlet of the spray head 8 with the cover plate 19, close the first valve 14, open the second valve 16, and start the circulation pump. Use the cleaning fluid in the first chamber to rinse the inside of the spray head 8. After rinsing, close the second valve 16 and the circulation pump, and open the cover plate 19 to reset. During the cleaning operation, the six-axis robot remains stationary to ensure the stability of the cleaning operation. After cleaning, the six-axis robot drives the spraying unit to reset, ready for the next layer of coating.

[0036] Step 5: Subsequent Coating Spraying. Repeat steps 3-4 to sequentially complete the spraying and cleaning of the second layer (transition layer) and the third layer (wear-resistant topcoat) until all coatings are sprayed. Cleaning is performed after each layer to prevent the mixing of different coating materials within the spraying system. During subsequent coating spraying, adjust the spraying speed, distance, and pressure of the six-axis robot according to the coating stacking requirements using the control system. For example, the spraying speed for the second transition layer is 60mm / s and the spraying distance is 170mm, while the spraying speed for the third topcoat is 70mm / s and the spraying distance is 190mm, ensuring uniform coating stacking and improving overall coating performance.

[0037] Step Six: Material Unloading Completed. After all coatings are applied, the conveyor plate 9 is moved to the unloading station via the conveyor unit. The positioning fixtures are removed, and the coated castings are removed using a crane for subsequent coating curing treatment (e.g., high-temperature curing, curing temperature 120℃, curing time 2 hours). Simultaneously, the device is thoroughly cleaned, removing any residual material from the storage tank 5, connecting tank 7, and spraying tank 6 to ensure no material residue remains in the spraying system, preparing for the next batch of castings. At this point, the six-axis robot returns to its initial standby state, completing one spraying cycle. Batch spraying parameters can be set via the control system to achieve continuous spraying of multiple batches of castings, improving production efficiency. The above is merely a preferred embodiment of the present invention and is not intended to limit the invention. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A spraying device for coating large machine tool castings, characterized in that, include: The base plate (1) is equipped with a conveying unit for conveying the main body of the casting. A spraying robotic arm (2) is mounted on the base plate (1) and has a spraying unit for spraying the casting body. The spraying unit includes: A spraying pump (3) is connected to a storage tank (5) via a connecting rigid pipe (4). The storage tank (5) is connected to a connecting box (7), which is connected to the spraying robotic arm (2). Different spraying materials are stored inside the connecting box (7). A spraying box (6) is connected to a connecting box (7) via a connecting rigid pipe (4). A spraying head (8) is fixedly connected to the spraying box (6). A cleaning unit for cleaning the inside of the spraying head (8) is provided on the outside of the spraying head (8). The cleaning unit includes: A scraping unit, which is located inside the spray box (6), is used to scrape off the spraying material adhering to the inner wall of the spray box (6), and a circulation unit is used to provide power for the scraping of the scraping unit.

2. The spraying device for coating large machine tool castings as described in claim 1, characterized in that, The conveying unit includes a conveying plate (9), which is connected to the base plate (1) via a guide rail (10), and a rotating plate (11) is rotatably connected to the conveying plate (9).

3. The spraying device for coating large machine tool castings as described in claim 2, characterized in that, The circulation unit includes a first connecting pipe (12), a second connecting pipe (13) is fixedly connected to the side of the first connecting pipe (12), the second connecting pipe (13) is connected to a first valve (14), a first connecting rod (15) is fixedly connected to the side of the first connecting pipe (12), a second valve (16) is fixedly connected to the end of the first connecting rod (15), the first connecting pipe (12) is fixedly connected to a third connecting pipe (17), the third connecting pipe (17) is rotatably connected to a fourth connecting pipe (18), the fourth connecting pipe (18) is provided with a cover plate (19) that cooperates with the spray head (8), a first box (20) is fixedly connected to the side of the spray box (6), the first box (20) is connected to the first valve (14) and the second valve (16) respectively through a connecting hose (21).

4. A spraying device for coating large machine tool castings as described in claim 3, characterized in that, The scraping unit includes a first rotating shaft (22) rotatably connected inside the spray box (6). A plurality of first scrapers (23) arranged in a circular array are fixedly connected to the side of the first rotating shaft (22). A second scraper (24) is inserted inside the first scraper (23). A scraping pad (25) is fixedly connected to the end of the second scraper (24).

5. A spraying device for coating large machine tool castings as described in claim 4, characterized in that, The first scraper (23) has a slot (26) inside, and the second scraper (24) is inserted into the first scraper (23). A guide plate (27) is fixedly connected to the side of the second scraper (24). A snap-fit ​​groove (28) is opened on the slot (26). A guide rod (29) is fixedly connected in the snap-fit ​​groove (28). The guide rod (29) passes through the guide plate (27). The guide plate (27) is connected to the inner wall of the snap-fit ​​groove (28) through a spring (30) for providing elasticity.

6. A spraying device for coating large machine tool castings as described in claim 5, characterized in that, The side of the first rotating shaft (22) is rotatably connected to a plurality of rotating blades (32) arranged in a circular array via a second rotating shaft (31), and a torsion spring (33) is provided on the outer side of the second rotating shaft (31).

7. A spraying device for coating large machine tool castings as described in claim 6, characterized in that, A limiting plate (34) for limiting the position of the rotating blade (32) is fixedly connected to the second rotating shaft (31).

8. A spraying device for coating large machine tool castings as described in claim 7, characterized in that, A filter layer (35) is fixedly connected inside the first housing (20).

9. A spraying device for coating large machine tool castings as described in claim 8, characterized in that, Both the first valve (14) and the second valve (16) are electromagnetic directional valves.

10. A spraying method for coating large machine tool castings, characterized in that, Using a spraying apparatus for coating large machine tool castings as described in any one of claims 1-9, the steps include: Step 1: Loading and positioning. Place the large machine tool casting to be sprayed on the rotating plate (11), and fix the casting with the positioning fixture to ensure that the casting does not move during the spraying process; drive the servo motor of the conveying unit to move the conveying plate (9) along the guide rail (10) to the spraying station. At this time, the spraying robot arm (2) is in the initial standby state. Step 2: Setting spraying parameters. According to the coating requirements of the casting (such as coating type, thickness, spraying pressure, etc.), the motion trajectory, spraying speed, working pressure and spraying time of each spraying pump (3) of the spraying robot arm (2) are set through the control system; at the same time, the working parameters of the cleaning unit are set, such as the rotation speed of the scraping unit and the duration of the cleaning operation. Step 3: First coating layer spraying. Start the spraying pump (3) and solenoid reversing valve corresponding to the first coating layer. The spraying robot arm (2) moves according to the set trajectory. The spraying head (8) sprays the first coating material evenly onto the surface of the casting. During the spraying process, according to the shape requirements of the casting, the rotating plate (11) is driven by the stepper motor to rotate and adjust the posture of the casting to ensure that all parts of the casting can be fully sprayed. After the spraying is completed, turn off the spraying pump (3) and solenoid reversing valve. Step 4: Cleaning operation. Start the cleaning unit, drive the motor to rotate the first rotating shaft (22), and scrape the first layer of coating material adhering to the inner wall of the spray box (6) by the scraping unit; at the same time, open the first valve (14), and the scraped material debris enters the first box (20) for filtration with the airflow. The filtered material is recycled to the recovery chamber of the connecting box (7); then rotate the fourth connecting pipe (18) so that the cover plate (19) covers the outlet of the spray head (8), close the first valve (14), open the second valve (16), start the circulation pump, and use the cleaning liquid in the first box (20) to rinse the inside of the spray head (8). After rinsing, close the second valve (16) and the circulation pump, and open the cover plate (19) to reset. Step 5: Subsequent Coating Spraying. Repeat steps 3-4 to complete the spraying and cleaning of the second, third, and subsequent coatings in sequence until all coatings are sprayed. After each coating is sprayed, perform a cleaning operation to avoid mixing of different coating materials in the spraying system. Step Six: Material Unloading Completed. After all coatings are applied, the conveyor plate (9) is moved to the unloading station via the conveyor unit, the positioning fixture is removed, and the coated castings are taken off for subsequent coating curing. At the same time, the device is thoroughly cleaned to ensure that there are no material residues in the coating system, in preparation for the coating of the next batch of castings.

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