Method for cleaning and detecting oil stains on outer surface of cylinder barrel of hydraulic oil cylinder coating line
By using a high-pressure steam cleaning system and fluorescent detection technology, combined with a parameter self-learning database, the problems of low oil stain cleaning efficiency and poor compatibility during the hydraulic cylinder coating process have been solved, achieving accurate detection and efficient cleaning, and improving the intelligence level of the equipment.
Patent Information
- Application Number
- CN202511428051.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2026-02-03
AI Technical Summary
In the existing hydraulic cylinder painting process, the oil stain cleaning methods are inefficient, have poor compatibility, waste cleaning resources, and lack detection accuracy, making it impossible to achieve intelligent management.
A high-pressure steam cleaning system combined with fluorescence detection and a parameter self-learning database is used to automatically identify the cylinder size, perform equal-area adaptive mesh division, and adjust cleaning parameters in real time to achieve precise control of oil content detection and cleaning.
It improves the accuracy of oil stain detection and cleaning efficiency, reduces resource waste, realizes intelligent management of equipment, and ensures cleaning effect.
Smart Images
Figure CN121452239A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of hydraulic cylinder coating technology, and more specifically, to a method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder coating line. Background Technology
[0002] Hydraulic cylinders are prone to corrosion failure during operation in the humid environment of underground mines. To extend their service life, the outer surface of the cylinder barrel is generally coated with a protective coating. This coating process is typically performed after all machining operations are completed. However, oil and cutting fluid mixtures from these machining processes can remain on the substrate surface. If not thoroughly cleaned, these oils can form a physical barrier, hindering direct contact between the coating and the substrate and significantly reducing coating adhesion. Furthermore, some oils contain silicones, fatty acids, or other components that may react with the coating or migrate into the coating's interior, disrupting interfacial chemical bonds and leading to a significant decline in coating performance.
[0003] Traditional methods for cleaning oil stains on the outer surface of hydraulic cylinder barrels are generally through-type cleaning methods, i.e., the cylinder barrel 1 is hoisted forward, and several drainage and washing nozzles 2 are installed on both sides of the cylinder barrel hoisting forward line, such as... Figure 1 As shown, cylinders of all diameters are cleaned using the same parameters, involving multiple steps including cleaning agent spraying, rinsing with clean water, and degreasing wash (with cleaning agent), rinsing with clean water, and rust-preventive wash. This multi-step process wastes resources. Furthermore, the cleaning agent is environmentally unfriendly, and residual chemicals can cause coating failure. Cleanliness is difficult to quantify, and there are no methods to test oil content; relying solely on experience or visual inspection to judge cleaning effectiveness can easily lead to over-cleaning or under-cleaning.
[0004] Currently, we are the first in the coal mining machinery industry to introduce steam degreasing technology. For each cylinder diameter and each level of oil residue, the same nozzle 3 (fixed spray width) is used for hand-held cleaning. Each time, nozzle 3 can only clean the area corresponding to one spray width. As the cylinder diameter increases, the central angle covered by one nozzle on the cylinder circumference decreases. Figure 2 As shown, a cylinder with a large diameter requires the nozzle 3 to travel multiple times to cover its entire surface, resulting in poor cleaning compatibility for cylinders with different diameters. Furthermore, cleaning parameters such as nozzle travel speed, nozzle pressure, and steam temperature are inflexible and cannot dynamically match the oil content: typically, the nozzle travels at the lowest speed (the speed required to clean the area with the highest oil content) throughout the entire stroke, resulting in extremely low cleaning efficiency and easily causing over-cleaning of areas with low oil content. Simultaneously, cleaning parameters such as nozzle pressure and steam temperature are set at their maximum values (the values required to clean the area with the highest oil content), further leading to over-cleaning of areas with low oil content and wasting cleaning resources. Similarly, judging oil content visually and relying on cleaning results is inaccurate and does not meet the requirements of intelligent development. Summary of the Invention
[0005] The purpose of this invention is to address the shortcomings of existing technologies by providing a method for cleaning and detecting oil stains on the outer surface of cylinder barrels in hydraulic cylinder painting lines. This invention can effectively improve the cleaning compatibility of cylinder barrels with different diameters, adaptively adjust cleaning parameters according to oil stain content, improve cleaning efficiency, avoid over-cleaning or under-cleaning, avoid waste of cleaning resources, significantly improve the accuracy of oil stain content detection, and has an incremental learning function, enabling the equipment to become smarter with use and ensuring cleaning results.
[0006] To achieve the above objectives, the technical solution adopted by this invention is: a method for cleaning and detecting oil stains on the outer surface of a hydraulic cylinder barrel in a painting line, specifically including the following steps: (a) The cylinder barrel is conveyed from front to back into the cleaning chamber by the painting line conveyor chain, so that the cylinder barrel stops at the cleaning station and is located between the high-pressure steam cleaning systems on the left and right sides of the cleaning station; the high-pressure steam cleaning system includes several nozzles arranged in an arc around the cylinder barrel, and the coverage areas of two adjacent nozzles are connected. (ii) The automatic identification system at the entrance of the cleaning chamber identifies the cylinder size information and the cylinder suspension height position and transmits the identification information to the control system; wherein, the cylinder size information includes the cylinder diameter and length; (iii) The control system compares the received cylinder size information with the cylinder model data in the database to accurately determine the cylinder diameter and length; (iv) The control system determines the number and sequence of nozzles to be opened in the high-pressure steam cleaning system based on the cylinder diameter and length. (v) Based on convergence analysis, perform equal-area adaptive mesh generation on the cylinder surface; (vi) Measure the oil content of each grid on the cylinder surface using a fluorescence detection system; (vii) Establish a parameter self-learning database that maps oil content to cleaning parameters in real time, and control the system to set cleaning parameters according to oil content; among which, cleaning parameters include nozzle travel speed, nozzle pressure and steam temperature; Based on the test results of salt spray resistance and pull-out strength of coatings with different oil content, a correlation model between oil content and coating quality was established to determine the oil content threshold that meets product requirements. (viii) Control the high-pressure steam cleaning system to move back and forth and clean the cylinder surface according to the cleaning parameters corresponding to each grid; (ix) Re-inspect the oil content of each grid on the cylinder surface, compare it with the oil content threshold, determine whether the cleaning effect is qualified, optimize the cleaning parameters through the parameter self-learning database, and clean the unqualified areas again until the cleaning effect is qualified.
[0007] Beneficial effects: (1) The present invention introduces a high-pressure steam cleaning system on both the left and right sides of the cleaning station. The high-pressure steam cleaning system includes several nozzles arranged in an arc around the cylinder. The coverage of two adjacent nozzles is connected. The control system determines the number and sequence of nozzle opening based on the cylinder diameter and length, so that the cylinder diameter is adapted to the coverage of the opened nozzles. In this way, the number of nozzles opening can be flexibly adjusted to adapt to the cleaning of cylinders with different cylinder diameters. For the cleaning of cylinders with large cylinder diameters, the number of times the nozzles travel can be effectively reduced. Thus, the present invention can effectively improve the compatibility of cleaning cylinders with different cylinder diameters. (2) Based on convergence analysis, the present invention performs equal-area adaptive mesh division on the cylinder surface to ensure that when detecting oil content in each mesh on the cylinder surface, a dynamic balance between oil content detection efficiency and detection accuracy is achieved. (3) The present invention measures the oil content of each grid on the cylinder surface by means of a fluorescence detection system, and calculates the oil content by means of fluorescence value, which significantly improves the accuracy of oil content detection. Compared with the traditional visual detection, the accuracy is improved by 200%, and the cleaning effect can be accurately detected by re-inspection. (4) The present invention establishes a parameter self-learning database that maps oil content and cleaning parameters in real time. When cleaning oil on the cylinder surface, the cleaning parameters such as nozzle travel speed, nozzle pressure and steam temperature can be adaptively adjusted according to the oil content of each grid on the cylinder surface. This avoids cleaning according to a single cleaning parameter that is most suitable for the oil content, thus improving cleaning efficiency, avoiding over-cleaning or under-cleaning, and avoiding waste of cleaning resources. (5) The present invention can optimize cleaning parameters through parameter self-learning database, has incremental learning function, realizes that the equipment becomes smarter the more it is used, and ensures cleaning effect.
[0008] Based on the above, the high-pressure steam cleaning system also includes a rail-mounted robotic arm, a high-pressure steam nozzle curved in an arc, and a high-pressure steam generator. The rail of the rail-mounted robotic arm is arranged in the cleaning chamber along the front-to-back direction. The robotic arm's hand moves back and forth on the rail. The wrist of the robotic arm's hand is equipped with a first wrist joint. The high-pressure steam nozzle is located at the end of the first wrist joint. Each nozzle is arranged in an arc on the high-pressure steam nozzle and is oriented towards the center of the circumference of the high-pressure steam nozzle. The high-pressure steam generator provides high-pressure steam to the high-pressure steam nozzle. The control system controls the operation of the rail-mounted robotic arm and the high-pressure steam generator, and controls the independent opening and closing of each nozzle.
[0009] Beneficial effects: The guide rail robotic arm can drive the nozzle to move at the corresponding nozzle walking speed and control the nozzle spray angle; the high-pressure steam generator is used to adjust the nozzle pressure and steam temperature.
[0010] Based on the above, the automatic identification system includes a workpiece detection sensor and an image recognition device installed at the entrance of the cleaning chamber. The control system is connected to the workpiece detection sensor and the image recognition device respectively. The workpiece detection sensor is used to detect the cylinder to trigger the control system to control the image recognition device to continuously identify the cylinder. The image recognition device is used to identify the cylinder size information and the cylinder suspension height position, and transmit the identification information to the control system.
[0011] Beneficial effects: The cylinder size information and cylinder suspension height position can be identified by the image recognition device installed at the entrance of the cleaning chamber, and triggered by the workpiece detection sensor. It is low cost and the recognition action is convenient and fast.
[0012] Based on the above, the fluorescence detection system includes a fluorescence sensor, and the robotic wrist of the guide rail robotic arm is also provided with a second wrist joint. The fluorescence sensor is located at the end of the second wrist joint, and the control system is connected to the fluorescence sensor signal.
[0013] Beneficial effects: The fluorescence sensor can monitor the fluorescence value in each grid, and then send the fluorescence value to the control system to calculate the oil content.
[0014] Based on the above, step (ii) is as follows: when the cylinder is conveyed by the coating line conveyor chain through the entrance of the cleaning chamber, the workpiece detection sensor detects the cylinder and triggers the control system to control the image recognition device to continuously identify the cylinder. The image recognition device identifies the cylinder size information and the cylinder suspension height position, and transmits the identification information to the control system.
[0015] Beneficial effect: The cylinder can be identified by following the above steps.
[0016] Based on the above, the number and sequence of nozzles opened in the high-pressure steam cleaning system in step (iv) are determined by the following logic: Assuming the number of nozzles is N, the nozzle sequence from top to bottom is L1, L2, ..., L... N First, determine the central angle θ1 corresponding to the coverage area of a nozzle on the cylinder circumference. If the central angle θ1 ≥ 90°, then determine that a nozzle is activated. Divide the cylinder surface corresponding to the nozzle into two axial regions, upper and lower, according to the nozzle coverage area. Activate nozzle L1 in the upper region and nozzle L2 in the lower region. N If the central angle θ1 < 90°, then the coverage area of the two consecutive nozzles is determined to be the central angle θ2 corresponding to the cylinder circumference. If the central angle θ2 ≥ 90°, then both nozzles are activated, and the cylinder side surface corresponding to the nozzles is divided into upper and lower regions along the axial direction according to the nozzle coverage area. Nozzles L1 and L2 are activated in the upper region, and nozzle L is activated in the lower region. N-1 L NThis process continues until it is determined that the coverage area of all open nozzles corresponds to the central angle θ on the cylinder circumference. N If the central angle θ N If the angle is ≥90°, then all nozzles are activated, and the cylinder surface corresponding to the nozzle is divided into upper and lower regions along the axial direction according to the nozzle coverage area; if the central angle θ N If the angle is less than 90°, the cylinder side surface corresponding to the nozzle will be divided into three regions along the axial direction according to the nozzle coverage range: upper, middle, and lower. All nozzles will be opened in the upper and lower regions. The above determination will be repeated in the middle region until the number and sequence of nozzles to be opened in the middle region are determined. The central angle is calculated by the following formula: θ=2arcsin(2r / L), where θ is the central angle corresponding to the coverage area of the opened nozzle on the circumference of the cylinder, r is the cylinder radius, and L is the spray width formed by the combination of opened nozzles.
[0017] Beneficial effects: Through the above steps, the number of nozzles opened can be flexibly adjusted to adapt to the cleaning of cylinders with different diameters. For the cleaning of cylinders with large diameters, the number of nozzle movements can be effectively reduced. Thus, the present invention can effectively improve the compatibility of cleaning cylinders with different diameters.
[0018] Based on the above, step (5) is as follows: Based on the convergence analysis, determine the area S of each grid, define the dimension Rd of each grid in the cylinder circumference direction as equal to the coverage area of the opened nozzle in the cylinder circumference direction, and then automatically adjust the dimension of each grid in the cylinder length direction to L=S / Rd. The area S of each grid is obtained by the following convergence analysis steps: the initial area of each grid is predefined to be equal to S1, then the grid is refined to reduce the area of each grid to S2, the deviation of the oil content values in the two grids is compared, the oil content value in the grid is taken as the average of the oil content of 5 points evenly distributed on the two body diagonals in the grid, if the deviation is within an acceptable error range (e.g., <5%), the grid is considered to have "converged", and the area of the grid that has converged and whose computational cost is acceptable is selected.
[0019] Beneficial effects: Through the above steps, the cylinder surface is divided into an adaptive grid with equal area, ensuring a dynamic balance between oil content detection efficiency and detection accuracy when detecting oil content in each grid on the cylinder surface.
[0020] Based on the above, step (vi) is as follows: the guide rail robotic arm and the second wrist joint drive the fluorescence sensor to scan the cylinder surface from top to bottom and from front to back, measure the fluorescence value in each grid on the cylinder surface, measure only one point in each grid, and the fluorescence sensor automatically feeds back the measured fluorescence value to the control system. The control system calculates the oil content of each grid based on the fluorescence value.
[0021] Beneficial effects: Through the above steps, the oil content of each grid can be calculated using fluorescence detection, which significantly improves the accuracy of oil content detection. Compared with traditional visual detection, the accuracy is improved by 200%, and the cleaning effect can be accurately detected through re-inspection.
[0022] Based on the above, step (eight) is as follows: the high-pressure steam nozzle and corresponding nozzles are driven by the guide rail robotic arm and the first wrist joint to clean the cylinder surface from top to bottom and from front to back. Each grid is matched with the corresponding cleaning parameters according to the oil content. At the same time, during the cleaning process, the fluorescent sensor is turned downward by the second wrist joint.
[0023] Beneficial effects: By following the above steps, cleaning parameters such as nozzle travel speed, nozzle pressure, and steam temperature can be adaptively adjusted, avoiding cleaning based on a single parameter that is most suitable for the highest oil content, thus improving cleaning efficiency, avoiding over-cleaning or under-cleaning, and avoiding waste of cleaning resources.
[0024] Based on the above, step (nine) is as follows: measure the oil content of each grid on the cylinder surface again using the fluorescence detection system. At this time, the measurement point of each grid is located at a different point than the measurement point of each grid in step (six). Compare the oil content of each grid at this time with the oil content threshold to determine whether the cleaning effect of each grid is qualified. If qualified, the coating line conveyor chain will transport the cylinder out of the cleaning chamber. If unqualified, the parameter self-learning database will automatically optimize and update the cleaning parameters. Control the high-pressure steam cleaning system to clean the unqualified grid area again according to the optimized cleaning parameters until the cleaning effect of each grid is qualified.
[0025] Beneficial effects: Through the above steps, the parameter self-learning database can optimize cleaning parameters, has an incremental learning function, and enables the equipment to become smarter with use, ensuring cleaning results. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the through-cleaning method.
[0027] Figure 2 This is a schematic diagram of a nozzle cleaning cylinders of different diameters.
[0028] Figure 3 This is a schematic diagram showing the arrangement of the coating line conveyor chain, high-pressure steam cleaning system, automatic identification system, control system, and fluorescence detection system in the cleaning chamber according to the present invention.
[0029] Figure 4 This is a rear view of the coating line conveyor chain, high-pressure steam cleaning system, automatic identification system, control system, and fluorescence detection system of the present invention arranged in the cleaning chamber.
[0030] Figure 5This is a right view of the arrangement of the coating line conveyor chain, high-pressure steam cleaning system, automatic identification system, control system and fluorescence detection system of the present invention in the cleaning chamber.
[0031] Figure 6 This is a schematic diagram of the high-pressure steam cleaning system of the present invention.
[0032] Figure 7 yes Figure 6 A magnified view of a portion of point A in the middle.
[0033] Figure 8 This is a schematic diagram illustrating the principle of the present invention for determining the number and sequence of nozzle openings for cleaning cylinders of different diameters.
[0034] In the diagram: 1. Cylinder; 2. Water washing nozzle; 3. Nozzle; 4. High-pressure steam cleaning system; 5. Automatic identification system; 6. Control system; 7. Guide rail robotic arm; 8. High-pressure steam nozzle; 9. First wrist joint; 10. Image recognition device; 11. Fluorescent sensor; 12. Second wrist joint. Detailed Implementation
[0035] The technical solution of the present invention will be further described in detail below through specific embodiments.
[0036] Example 1 like Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, a method for cleaning and detecting oil stains on the outer surface of a hydraulic cylinder barrel in a painting line includes the following steps: (a) The cylinder 1 is conveyed from front to back into the cleaning chamber by the painting line conveyor chain, so that the cylinder 1 stops at the cleaning station and is located between the high-pressure steam cleaning system 4 on the left and right sides of the cleaning station; the high-pressure steam cleaning system 4 includes a number of nozzles 3 arranged in an arc around the cylinder 1, and the coverage areas of two adjacent nozzles 3 are connected. (ii) The automatic identification system 5 at the entrance of the cleaning chamber identifies the size information of cylinder 1 and the suspension height position of cylinder 1 and transmits the identification information to the control system 6; wherein, the size information of cylinder 1 includes cylinder diameter and length; (iii) The control system 6 compares the received cylinder barrel 1 size information with the cylinder barrel model data in the database to accurately determine the cylinder diameter and length of cylinder barrel 1; (iv) The control system 6 determines the number and sequence of nozzles to be opened in the high-pressure steam cleaning system 4 based on the cylinder diameter and length of the cylinder 1; (v) Based on convergence analysis, perform equal-area adaptive mesh generation on the surface of cylinder 1; (vi) Measure the oil content of each grid on the surface of cylinder 1 using a fluorescence detection system; (vii) Establish a parameter self-learning database that maps oil content to cleaning parameters in real time, and control system 6 sets cleaning parameters according to oil content; among which, cleaning parameters include nozzle travel speed, nozzle pressure and steam temperature; Based on the test results of salt spray resistance and pull-out strength of coatings with different oil content, a correlation model between oil content and coating quality was established to determine the oil content threshold that meets product requirements. (viii) Control the high-pressure steam cleaning system 4 to move back and forth and clean the surface of cylinder 1 according to the cleaning parameters corresponding to each grid; (ix) Re-inspect the oil content of each grid on the surface of cylinder barrel 1, compare it with the oil content threshold, determine whether the cleaning effect is qualified, optimize the cleaning parameters through parameter self-learning database, and clean the unqualified areas again until the cleaning effect is qualified.
[0037] It should be noted that the oil content threshold in step (vii) is specifically determined by the following steps: (1) preparing coating test plates with different oil contents; (2) testing the salt spray resistance and pull-out strength of coating test plates with different oil contents; (3) obtaining the salt spray resistance duration and pull-out value changes of coating test plates with different oil contents, and then establishing a correlation model between oil content and coating quality; (4) determining the oil content threshold that meets the product requirements based on the salt spray resistance duration and pull-out value requirements of the product.
[0038] This invention can flexibly adjust the number of nozzles opened to adapt to the cleaning of cylinders 1 with different diameters. For cleaning cylinders 1 with large diameters, it can effectively reduce the number of times the nozzles 3 travel, thereby effectively improving the compatibility of cleaning cylinders 1 with different diameters.
[0039] This invention performs equal-area adaptive meshing on the surface of cylinder barrel 1 based on convergence analysis, ensuring a dynamic balance between oil content detection efficiency and detection accuracy when detecting oil content in each mesh on the surface of cylinder barrel 1.
[0040] This invention measures the oil content of each grid on the surface of cylinder 1 using a fluorescence detection system, and calculates the oil content using fluorescence values, which significantly improves the accuracy of oil content detection. Compared with traditional visual detection, the accuracy is improved by 200%, and the cleaning effect can be accurately detected through re-inspection.
[0041] This invention establishes a parameter self-learning database that maps oil content to cleaning parameters in real time. When cleaning oil on the surface of cylinder 1, the cleaning parameters such as nozzle travel speed, nozzle pressure, and steam temperature can be adaptively adjusted according to the detected oil content of each grid on the surface of cylinder 1. This avoids cleaning according to a single cleaning parameter that maximizes the oil content, thereby improving cleaning efficiency, avoiding over-cleaning or under-cleaning, and preventing waste of cleaning resources.
[0042] This invention optimizes cleaning parameters through a parameter self-learning database, has an incremental learning function, and enables the equipment to become smarter with use, ensuring cleaning results.
[0043] Example 2 like Figure 3 , Figure 4 , Figure 5 , Figure 6 and Figure 7 As shown, based on Embodiment 1, the high-pressure steam cleaning system 4 further includes a guide rail robotic arm 7, a high-pressure steam nozzle 8 curved in an arc, and a high-pressure steam generator (not shown). The track of the guide rail robotic arm 7 is arranged in the cleaning chamber along the front-to-back direction. The robotic arm 7 moves back and forth on the track. The wrist of the robotic arm 7 is provided with a first wrist joint 9. The high-pressure steam nozzle 8 is located at the end of the first wrist joint 9. Each nozzle 3 is arranged in an arc on the high-pressure steam nozzle 8 and is oriented towards the center of the circumference of the high-pressure steam nozzle 8. The high-pressure steam generator provides high-pressure steam to the high-pressure steam nozzle 8. The control system 6 controls the operation of the guide rail robotic arm 7 and the high-pressure steam generator respectively, and controls each nozzle 3 to open and close independently.
[0044] The automatic identification system 5 includes a workpiece detection sensor and an image recognition device 10 installed at the entrance of the cleaning chamber. The control system 6 is connected to the workpiece detection sensor and the image recognition device 10 respectively. The workpiece detection sensor is used to detect the cylinder 1 to trigger the control system 6 to control the image recognition device 10 to continuously identify the cylinder 1. The image recognition device 10 is used to identify the size information of the cylinder 1 and the suspension height position of the cylinder 1, and transmit the identification information to the control system 6.
[0045] The fluorescence detection system includes a fluorescence sensor 11. The robotic arm 7 has a second wrist joint 12 at its wrist, and the fluorescence sensor 11 is located at the end of the second wrist joint 12. The control system 6 is connected to the fluorescence sensor 11. The fluorescence sensor 11 is used to measure the fluorescence value of the irradiated surface.
[0046] Example 3 Based on Example 2, step (2) is as follows: When the cylinder 1 is conveyed by the coating line conveyor chain through the entrance of the cleaning chamber, the workpiece detection sensor detects the cylinder 1 and triggers the control system 6 to control the image recognition device 10 to continuously recognize the cylinder 1. The image recognition device 10 recognizes the size information of the cylinder 1 and the suspension height position of the cylinder 1, and transmits the recognition information to the control system 6.
[0047] Example 4 Based on Example 1, such as Figure 8As shown, the number and sequence of nozzles opened in the high-pressure steam cleaning system 4 in step (iv) are determined by the following logic: Assuming there are 5 nozzles 3, the nozzle sequence from top to bottom is L1, L2, ..., L5; First, determine the central angle θ1 corresponding to the coverage area of a nozzle 3 on the circumference of cylinder 1. If the central angle θ1 ≥ 90°, then determine that a nozzle 3 is opened, and divide the surface of one side of cylinder 1 corresponding to the nozzle 3 into two regions along the axial direction according to the nozzle coverage area. The upper region opens nozzle L1, and the lower region opens nozzle L5. N If the central angle θ1 < 90°, then determine the central angle θ2 corresponding to the coverage area of two consecutive nozzles 3 on the circumference of cylinder 1. If the central angle θ2 ≥ 90°, then determine that two nozzles 3 are activated, and divide the surface of one side of cylinder 1 corresponding to nozzle 3 into two regions along the axial direction according to the nozzle coverage area. Activate nozzles L1 and L2 in the upper region, and activate nozzles L4 and L5 in the lower region. Continue in this manner until it is determined that the central angle θ5 corresponding to the coverage area of all nozzles 3 on the circumference of cylinder 1 is activated. If the central angle θ5 ≥ 90°, then determine that all nozzles 3 are activated, and divide the surface of one side of cylinder 1 corresponding to nozzle 3 into two regions along the axial direction according to the nozzle coverage area. If the central angle θ5 < 90°, divide the surface of one side of cylinder 1 corresponding to nozzle 3 into three regions along the axial direction according to the nozzle coverage area: upper, middle, and lower. Activate all nozzles 3 in both the upper and lower regions. Repeat the above determination for the middle region until the number and sequence of activated nozzles in the middle region are determined. The central angle is calculated by the following formula: θ=2arcsin(2r / L), where θ is the central angle corresponding to the coverage area of the opened nozzle 3 on the circumference of the cylinder 1, r is the radius of the cylinder 1, and L is the spray width formed by the combination of the opened nozzles 3.
[0048] Step (5) is as follows: Based on the convergence analysis, determine the area S of each grid, define the dimension Rd of each grid in the circumferential direction of cylinder 1 as equal to the coverage area of the opened nozzle 3 in the circumferential direction of cylinder 1, and then automatically adjust the dimension of each grid in the length direction of cylinder 1 to L=S / Rd. The area S of each grid is obtained by the following convergence analysis steps: the initial area of each grid is predefined to be equal to S1, then the grid is refined to reduce the area of each grid to S2, the deviation of the oil content values in the two grids is compared, the oil content value in the grid is taken as the average of the oil content of 5 points evenly distributed on the two body diagonals in the grid, if the deviation is within an acceptable error range (e.g., <5%), the grid is considered to have "converged", and the area of the grid that has converged and whose computational cost is acceptable is selected.
[0049] Since the oil content of the grid is characterized by fluorescence measurement points, if the area is too large, the fluorescence characterization value will differ from the actual fluorescence amount of the entire grid, resulting in inaccurate oil content detection, unsuitable matching cleaning parameters, and consequently, failure to guarantee cleaning effectiveness. If the area is too small, there will be too many grid divisions, leading to a large number of detections and low detection efficiency. The grid division method in step (five) can determine the most suitable grid area, enabling cylinders of different diameters to undergo equal-area adaptive grid division with the most suitable grid area, achieving a dynamic balance between oil content detection efficiency and detection accuracy.
[0050] Example 5 Based on Example 2, step (six) is as follows: the guide rail robotic arm 7 and the second wrist joint 12 drive the fluorescence sensor 11 to scan the surface of the cylinder 1 from top to bottom and from front to back, measure the fluorescence value in each grid on the surface of the cylinder 1, and measure only one point in each grid. The fluorescence sensor 11 automatically feeds back the measured fluorescence value to the control system 6, and the control system 6 calculates the oil content of each grid based on the fluorescence value.
[0051] Step (eight) is as follows: the high-pressure steam nozzle 8 and the corresponding nozzle 3 are driven by the guide rail robotic arm 7 and the first wrist joint 9 to clean the surface of the cylinder 1 from top to bottom and from front to back. Each grid is matched with the corresponding cleaning parameters according to the oil content. At the same time, during the cleaning process, the fluorescent sensor 11 is turned downward by the second wrist joint 12 to prevent steam from entering the interior of the fluorescent sensor 11.
[0052] Step (nine) specifically involves: measuring the oil content of each grid on the surface of cylinder 1 again using the fluorescence detection system. At this time, the measurement point of each grid is located at a different point than the measurement point of each grid in step (six). The oil content of each grid at this time is compared with the oil content threshold to determine whether the cleaning effect of each grid is qualified. If qualified, the coating line conveyor chain transports cylinder 1 out of the cleaning chamber. If unqualified, the parameter self-learning database automatically optimizes and updates the cleaning parameters, such as increasing the nozzle pressure or reducing the walking speed, to achieve adaptive adjustment of cleaning parameters. The equipment becomes more intelligent with use. The high-pressure steam cleaning system 4 is controlled to clean the unqualified grid area again according to the optimized cleaning parameters until the cleaning effect of each grid is qualified. Since the fluorescent material on the surface of the workpiece will undergo a photochemical reaction after the fluorescence emitter is irradiated by the receiver, the intensity of the secondary irradiation signal will decrease. Therefore, the measurement point of each grid in step (six) and the measurement point of each grid in step (nine) cannot be located at the same point.
[0053] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them; although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of the present invention or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solutions of the present invention, and all such modifications and substitutions should be covered within the scope of the technical solutions claimed in the present invention.
Claims
1. A method for cleaning and detecting oil stains on the outer surface of a hydraulic cylinder barrel in a painting line, characterized in that: Specifically, the following steps are included: (a) The cylinder barrel is conveyed from front to back into the cleaning chamber by the painting line conveyor chain, so that the cylinder barrel stops at the cleaning station and is located between the high-pressure steam cleaning systems on the left and right sides of the cleaning station; the high-pressure steam cleaning system includes several nozzles arranged in an arc around the cylinder barrel, and the coverage areas of two adjacent nozzles are connected. (ii) The automatic identification system at the entrance of the cleaning chamber identifies the cylinder size information and the cylinder suspension height position and transmits the identification information to the control system; wherein, the cylinder size information includes the cylinder diameter and length; (iii) The control system compares the received cylinder size information with the cylinder model data in the database to accurately determine the cylinder diameter and length; (iv) The control system determines the number and sequence of nozzles to be opened in the high-pressure steam cleaning system based on the cylinder diameter and length. (v) Based on convergence analysis, perform equal-area adaptive mesh generation on the cylinder surface; (vi) Measure the oil content of each grid on the cylinder surface using a fluorescence detection system; (vii) Establish a parameter self-learning database that maps oil content to cleaning parameters in real time, and control the system to set cleaning parameters according to oil content; among which, cleaning parameters include nozzle travel speed, nozzle pressure and steam temperature; Based on the test results of salt spray resistance and pull-out strength of coatings with different oil content, a correlation model between oil content and coating quality was established to determine the oil content threshold that meets product requirements. (viii) Control the high-pressure steam cleaning system to move back and forth and clean the cylinder surface according to the cleaning parameters corresponding to each grid; (ix) Re-inspect the oil content of each grid on the cylinder surface, compare it with the oil content threshold, determine whether the cleaning effect is qualified, optimize the cleaning parameters through the parameter self-learning database, and clean the unqualified areas again until the cleaning effect is qualified.
2. The method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder painting line according to claim 1, characterized in that: The high-pressure steam cleaning system also includes a rail-mounted robotic arm, a high-pressure steam nozzle curved in an arc, and a high-pressure steam generator. The rail-mounted robotic arm's track is arranged in the cleaning chamber along the front-to-back direction. The robotic arm's hand moves back and forth on the track. The robotic arm's wrist is equipped with a first wrist joint. The high-pressure steam nozzle is located at the end of the first wrist joint. Each nozzle is arranged in an arc on the high-pressure steam nozzle, and each nozzle is oriented towards the center of the circumference of the high-pressure steam nozzle. The high-pressure steam generator provides high-pressure steam to the high-pressure steam nozzle. The control system controls the operation of the rail-mounted robotic arm and the high-pressure steam generator, and controls the independent opening and closing of each nozzle.
3. The method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder painting line according to claim 1, characterized in that: The automatic identification system includes a workpiece detection sensor and an image recognition device installed at the entrance of the cleaning chamber. The control system is connected to the workpiece detection sensor and the image recognition device respectively. The workpiece detection sensor is used to detect the cylinder to trigger the control system to control the image recognition device to continuously identify the cylinder. The image recognition device is used to identify the cylinder size information and the cylinder suspension height position, and transmits the identification information to the control system.
4. The method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder painting line according to claim 2, characterized in that: The fluorescence detection system includes a fluorescence sensor. The robotic arm also has a second wrist joint at its wrist, and the fluorescence sensor is located at the end of the second wrist joint. The control system is connected to the fluorescence sensor signal.
5. The method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder painting line according to claim 3, characterized in that: Step (II) is as follows: When the cylinder is conveyed by the coating line conveyor chain through the entrance of the cleaning chamber, the workpiece detection sensor detects the cylinder and triggers the control system to control the image recognition device to continuously identify the cylinder. The image recognition device identifies the cylinder size information and the cylinder suspension height position, and transmits the identification information to the control system.
6. The method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder painting line according to claim 1, characterized in that: The number and sequence of nozzles opened in the high-pressure steam cleaning system in step (iv) are determined by the following logic: Assuming there are N nozzles, the nozzle sequence from top to bottom is L1, L2, ..., L... N First, determine the central angle θ1 corresponding to the coverage area of a nozzle on the cylinder circumference. If the central angle θ1 ≥ 90°, then determine that a nozzle is activated. Divide the cylinder surface corresponding to the nozzle into two axial regions, upper and lower, according to the nozzle coverage area. Activate nozzle L1 in the upper region and nozzle L2 in the lower region. N If the central angle θ1 < 90°, then the coverage area of the two consecutive nozzles is determined to be the central angle θ2 corresponding to the cylinder circumference. If the central angle θ2 ≥ 90°, then both nozzles are activated, and the cylinder side surface corresponding to the nozzles is divided into upper and lower regions along the axial direction according to the nozzle coverage area. Nozzles L1 and L2 are activated in the upper region, and nozzle L is activated in the lower region. N-1 L N This process continues until it is determined that the coverage area of all open nozzles corresponds to the central angle θ on the cylinder circumference. N If the central angle θ N If the angle is ≥90°, then all nozzles are activated, and the cylinder surface corresponding to the nozzle is divided into upper and lower regions along the axial direction according to the nozzle coverage area; if the central angle θ N If the angle is less than 90°, the cylinder side surface corresponding to the nozzle will be divided into three regions along the axial direction according to the nozzle coverage range: upper, middle, and lower. All nozzles will be opened in the upper and lower regions. The above determination will be repeated in the middle region until the number and sequence of nozzles to be opened in the middle region are determined. The central angle is calculated by the following formula: θ=2arcsin(2r / L), where θ is the central angle corresponding to the coverage area of the opened nozzle on the circumference of the cylinder, r is the cylinder radius, and L is the spray width formed by the combination of opened nozzles.
7. The method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder painting line according to claim 1, characterized in that: Step (5) is as follows: Based on the convergence analysis, determine the area S of each grid, define the dimension Rd of each grid in the cylinder circumference direction as equal to the coverage area of the opened nozzle in the cylinder circumference direction, and then automatically adjust the dimension of each grid in the cylinder length direction to L=S / Rd; The area S of each grid is obtained by the following convergence analysis steps: the initial area of each grid is predefined to be equal to S1, then the grid is refined to reduce the area of each grid to S2, the deviation of the oil content value in the two grids is compared, the oil content value in the grid is taken as the average of 5 points evenly distributed on the two body diagonals in the grid, if the deviation is within an acceptable error range, the grid is considered to have "converged"; the area of the grid that has converged and whose computational cost is acceptable is selected.
8. The method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder painting line according to claim 4, characterized in that: Step (six) is as follows: The guide rail robotic arm and the second wrist joint drive the fluorescence sensor to scan the cylinder surface from top to bottom and from front to back, and measure the fluorescence value in each grid on the cylinder surface. Only one point is measured in each grid. The fluorescence sensor automatically feeds back the measured fluorescence value to the control system. The control system calculates the oil content of each grid based on the fluorescence value.
9. The method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder painting line according to claim 8, characterized in that: Step (eight) specifically involves: using a guide rail robotic arm and the first wrist joint to drive the high-pressure steam jet and corresponding nozzles to clean the cylinder surface from top to bottom and from front to back, with each grid matching the corresponding cleaning parameters according to the oil content; at the same time, during the cleaning process, the second wrist joint is used to make the fluorescent sensor face downwards.
10. The method for cleaning and detecting oil stains on the outer surface of the cylinder barrel in a hydraulic cylinder painting line according to claim 8, characterized in that: Step (nine) is as follows: The oil content of each grid on the cylinder surface is measured again by the fluorescence detection system. At this time, the measurement point of each grid is located at a different point than the measurement point of each grid in step (six). The oil content of each grid at this time is compared with the oil content threshold to determine whether the cleaning effect of each grid is qualified. If qualified, the coating line conveyor chain will transport the cylinder out of the cleaning chamber. If unqualified, the parameter self-learning database will automatically optimize and update the cleaning parameters. The high-pressure steam cleaning system will be controlled to clean the unqualified grid area again according to the optimized cleaning parameters until the cleaning effect of each grid is qualified.