A back-loading hatch cover segment folding manufacturing process

Abstract

The application discloses a back-loading hatch cover segment folding manufacturing process, which comprises a hatch cover segment manufacturing process and a hatch cover folding manufacturing process.The hatch cover segment manufacturing process comprises material preparation, segment group welding, turning-over explosive correction, turning-over total group folding welding and bottom plate and box foot installation.In the segment group welding, the segment reverse deformation amount of the hatch cover is adjusted through middle group rack setting to form a first reverse deformation arch structure in which the hatch cover segments are convex in the middle and droop around the periphery.In the turning-over total group folding welding, the total group reverse deformation amount of the hatch cover is adjusted through the pier total group rack before welding to form a second reverse deformation arch structure in which the hatch cover is convex in the middle and droop around the periphery.The application solves the problems of large explosive correction workload, poor size stability and insufficient support matching precision in the existing back-loading hatch cover manufacturing, and can significantly improve the geometric precision and structural stability of the hatch cover.

Description

Technical Field

[0001] This invention relates to the field of marine technology, specifically to a manufacturing process for a segmented assembly of a back-mounted hatch cover. Background Technology

[0002] The back-mounted hatch cover is a key structure in container ships for enabling the simultaneous opening of two hatches. It is typically installed in pairs on adjacent hatches. Its core principle is that a horizontally movable hatch cover "carries" a retractable hatch cover that can be raised and lowered via a lifting mechanism, saving deck space and improving operational efficiency. When the first hatch needs to be opened, the lifting mechanism first raises the retractable hatch cover located at the second hatch position to form a high-level hatch cover. Then, the horizontally movable hatch cover at the first hatch position is moved below the high-level hatch cover using rollers, opening the first hatch. To open the second hatch, the lifting mechanism lowers the retractable hatch cover located at the second hatch position, allowing it to be supported by several support legs and placed on top of the horizontally movable hatch cover. The horizontally movable hatch cover then "carries" the retractable hatch cover, moving together to open the second hatch.

[0003] Hatch covers are large structural components. Due to their special operating conditions—the lower hatch cover needs to bear the entire weight of the higher hatch cover and evenly transfer the load through the distributed support legs—extremely high requirements are placed on the manufacturing precision of the hatch cover. In particular, the flatness of the top / bottom surface of the hatch cover, the levelness of the four corners, and the matching of the support structure need to be ensured.

[0004] The existing manufacturing process has the following three major bottlenecks: First, flame straightening is labor-intensive and highly dependent on the process: large deformation after welding requires extensive flame straightening, which is not only inefficient but also introduces secondary thermal stress, which degrades material properties.

[0005] Secondly, poor dimensional consistency: After welding the same design in sections and in the final assembly, inconsistent deformation will occur, resulting in uneven stress on the supporting parts of the paired hatch covers when they are loaded, which affects their stability, reliability and safety.

[0006] Third, the quality process control is relatively crude: there is a lack of quantitative monitoring and closed-loop control methods for reverse deformation, bonding state, and residual stress.

[0007] Therefore, there is an urgent need for a new process for manufacturing back-mounted hatch covers that can achieve high precision, low stress, and repeatability. Summary of the Invention

[0008] To address the aforementioned problems, this invention proposes a segmented assembly manufacturing process for back-loaded hatch covers. This process aims to solve issues such as the large workload of pyrotechnic straightening, poor dimensional stability, and insufficient support matching accuracy in existing back-loaded hatch cover manufacturing. It provides an intelligent segmented assembly manufacturing process integrating anti-deformation pre-control, welding excitation, staged vibration aging, self-weight bonding and shaping, online measurement feedback, and cyclic control optimization, significantly improving the geometric accuracy and structural stability of the hatch cover. The specific technical solution is as follows: A manufacturing process for segmented and assembled hatch covers, comprising a segmented hatch cover manufacturing process and a hatch cover assembly manufacturing process, wherein the segmented hatch cover manufacturing process includes the following steps: (1) Material preparation: Cut materials according to the design drawings. When cutting materials, add corresponding welding shrinkage allowance and fire straightening shrinkage allowance to the main components in the length and width directions of the hatch cover; wherein, the main components include the top plate and reinforcing components, as well as the end plate, side plate and reinforcing components; (2) Segmented assembly and welding: The hatch cover is divided into two segments and manufactured separately. When manufacturing segments, the first group assembly and welding are carried out, and then the middle group assembly and welding are carried out. Among them, the middle group assembly and welding of the hatch cover adopts the reverse construction method with the top plate at the bottom. That is, the top plate of the hatch cover is placed on the middle group jig for positioning and marking. The four corners of the top plate are limited by the jig. Then the structural components are installed on the top plate. Note that the bottom plate is not installed yet. After completion, the middle group welding is carried out. When welding the middle group, the intersection area of ​​the cross beam and the longitudinal beam, as well as the four corner areas of the hatch cover, are fixed with pressure irons to reduce the deformation of the top plate. (3) Turning over and fire correction: After the hatch cover is welded in sections, it is turned over and installed on the pier assembly jig for fire correction; the fire correction adopts the method of line heating and plane correction; the fire correction includes correcting the top plate plane, removing stress from the structural hardening, adjusting the closing joint, adjusting the four corners of the hatch cover to be level, and checking the straightness of the side plates and end plates around the hatch cover. In step (2) segmented welding, the segmented anti-deformation amount of the hatch cover is set and adjusted by the middle group jig to form a first anti-deformation arch structure in which the hatch cover segments are raised in the middle and drooping around the perimeter.

[0009] By setting the first anti-deformation arch structure, the hatch cover segments can form a flat top and bottom structure by their own weight after welding and in a free-support state.

[0010] In this invention, the hatch cover closing manufacturing process further includes the following steps set after the turning and fire correction in step (3): (4) Turning over and welding the assembly: After the hatch cover is fire-corrected, it is turned over again and installed and positioned on the pier assembly jig for assembly and welding. (5) Installation of bottom plate and box feet: Install the bottom plate and seal it; after the bottom plate is installed and welded, install and weld the box feet; In step (4) of the welding process, the overall anti-deformation of the hatch cover is adjusted by the jig of the pier assembly before welding, so that the hatch cover is a second anti-deformation arch structure with a raised center and a drooping perimeter.

[0011] By setting up a second anti-deformation arch structure, the hatch cover can form a flat structure on the top and bottom surfaces by its own weight when it is closed, welded and in a free-supported state.

[0012] As a further improvement of the present invention, the pier assembly frame includes an assembly base and N lifting piers distributed on the assembly base; each lifting pier includes a servo lifter and a ball joint top block rotatably mounted on the top of the lifting column of the servo lifter via a ball joint joint, and a spring is provided on the back of the ball joint top block to automatically straighten the ball joint top block; a through hole is provided in the center of the ball joint top block, and an infrared ranging sensor whose detection light can pass through the through hole is provided at the top of the servo lifter.

[0013] Preferably, the spring is a disc spring with a central through hole.

[0014] Preferably, the servo lifter is a servo lifting hydraulic cylinder or a servo lifting electric cylinder, which can adjust the lifting height through servo control.

[0015] In this invention, the servo lift and the infrared ranging sensor are respectively connected to the controller.

[0016] Preferably, the base of the main assembly is also provided with a number of level seats, and a ball joint top block is rotatably provided on the level seat via a ball joint pair; the ball joint top block located on the lifting support can be raised or lowered by the servo lifter to be higher or lower than the ball joint top block on the level seat; the servo lifter is also provided with an exciter for driving the lifting column of the servo lifter to make up-down micro-vibrations.

[0017] Preferably, the leveling seats are arranged along the two sides and four corners of the hatch cover to simulate the actual support of the hatch cover in use.

[0018] By setting up an equal-height platform, the number of servo lifters can be reduced. Furthermore, when the servo lifters are driven to descend, the hatch cover can sit freely on the ball joint top block of the equal-height platform, facilitating the detection of the hatch cover's flatness in a free-supported state.

[0019] Preferably, the vibrator includes an auxiliary hydraulic chamber integrally disposed next to the main hydraulic chamber of the servo lift, a partition wall disposed between the main hydraulic chamber and the auxiliary hydraulic chamber, a cylindrical shaft disposed on the partition wall to separate the main hydraulic chamber from the auxiliary hydraulic chamber, a micro-eccentric column disposed on the cylindrical shaft, and a servo motor for driving the cylindrical shaft and the micro-eccentric column to rotate together. The eccentric side of the micro-eccentric column can be driven to rotate by the servo motor and alternately enter the main hydraulic chamber and the auxiliary hydraulic chamber to realize the pulsation of hydraulic oil in the main hydraulic chamber.

[0020] Preferably, the servo motor is a variable frequency servo motor, thereby making the vibrator a hydraulic pulsating variable frequency vibrator.

[0021] In this invention, both the first anti-deformation arch structure and the second anti-deformation arch structure are implemented by controlling different lifting amounts of each of the servo lifters.

[0022] Preferably, the hatch cover segment manufacturing process further includes the following steps after the bottom sealing plate in step (5): (6) Installation of the back load support structure: The back load support structure includes a support block set on the top surface of one of the horizontally movable hatch covers in a pair of back load hatch covers, and a support leg set on the bottom surface of the other movable hatch cover in a pair of back load hatch covers; the height data of each support part on the bottom surface of the movable hatch cover is measured using a total station, and the leg length of the support leg with a margin is corrected according to the height data of each support part before being welded to the support part on the bottom surface of the movable hatch cover; after the support leg on the bottom surface of the movable hatch cover is installed and welded, the thickness dimension data of the support block on the top surface of the horizontally movable hatch cover is detected and determined by conducting a back load test on a pair of back load hatch covers, and the thickness of the support block with a margin is corrected according to the detected thickness dimension data of the support block before being installed and welded to the support part on the top surface of the horizontally movable hatch cover.

[0023] Preferably, the installation of the back load support structure in step (6) further includes the installation of an alignment structure, which includes a guide block disposed on the top side of the horizontally movable hatch cover and a limiting block disposed on the bottom side of the liftable hatch cover and adapted to the side of the guide block; the limiting block is temporarily spot welded before the back load test and is properly welded during the back load test.

[0024] As a further improvement, in the segmented welding of (2), the pressure iron used is a gravity pressure iron that is pressed by gravity. It is fixedly connected to the hatch cover by spot welding, and a variable frequency vibrator is installed on the gravity pressure iron. After the segmented welding is completed, the variable frequency vibrator is turned on, and each variable frequency vibrator uses the same excitation frequency to perform overall vibration aging treatment on the segments of the welded hatch cover.

[0025] Preferably, the variable frequency vibrator is equipped with a magnetic chuck, which fixes the vibrator to the gravity clamp for easy and quick assembly and disassembly. The magnetic chuck can be a permanent magnet or an electromagnet.

[0026] Preferably, the intermediate tire frame is placed on the working platform, and a vibration isolation pad is provided between the intermediate tire frame and the working platform.

[0027] Preferably, the vibration isolation pad has a double-layer structure, with an asbestos pad on top and a rubber pad on the bottom.

[0028] Preferably, the frequency converter is an eccentric motor frequency converter.

[0029] Furthermore, in step (4) of the overturning assembly welding, after the welding is completed, the vibrator on the servo lift of the pier assembly jig is turned on to perform vibration aging treatment on the hatch cover, thereby improving the overall deformation resistance and stability of the hatch cover after welding.

[0030] Furthermore, in step (3) of the fire correction, the vibrator on the servo lift of the pier assembly frame is simultaneously turned on while the fire correction is being performed, so as to achieve variable fire correction and stress relief by vibration aging.

[0031] As a further improvement of the present invention, in step (4) of the overturning assembly welding, the vibration aging treatment of the hatch cover after the welding is completed adopts a five-stage cyclic control strategy of "lifting-vibration-self-weight contact-measurement-anti-deformation lifting amount setting"; the five-stage cyclic control strategy of "lifting-vibration-self-weight contact-measurement-anti-deformation lifting amount setting" includes the following process: The first stage of lifting and anti-deformation: set the lifting amount of each servo lifter, lift the hatch cover as a whole through the servo lifter, so that the hatch cover is disengaged from the ball joint top block on the equal height seat, and form a certain amount of anti-deformation correction at the part of the servo lifter supporting the hatch cover. The second stage of vibration: turn on the vibrator on the servo lift and perform vibration aging treatment on the hatch cover for a period of time. The third stage of self-weight bonding: After vibration aging treatment, the servo lift descends until the ball joint top block above it is at the same height as the ball joint top block above the equal height seat. Under its own weight, the hatch cover is supported in a free state on each ball joint top block and automatically bonded for a period of time, so that the planar shape of the hatch cover is accurate. The fourth stage of measurement: When the automatic folding time is up, each servo lifter continues to descend to the set value, so that the ball joint top block on it is completely disengaged from the hatch cover, so that the hatch cover sits only on the ball joint top block of the equal height seat; after it is in place, the infrared ranging sensors on each servo lifter are activated, and the control system obtains the different sags of the hatch cover support part under its own weight through the ranging data of each infrared ranging sensor, and sets the lifting amount for the next lifting and anti-deformation according to the different sags, and then returns to the first stage of lifting and anti-deformation; The fifth stage anti-deformation lifting amount setting: Based on the measurement results of the fourth stage, the flatness of the hatch cover is evaluated, and then a new anti-deformation lifting amount is set for the first stage of lifting anti-deformation during cyclic control. The above five-stage cyclical control strategy is used until the flatness of the hatch cover reaches the preset optimal state.

[0032] The optimal state can be an absolute value of hatch cover flatness, or it can be the improvement in hatch cover flatness between two consecutive cycles. For example, the optimal state is reached when the difference in hatch cover flatness data is less than a certain set value after several cycles.

[0033] As a further improvement of the present invention, in the segmented welding of step (2), the variable frequency vibrator can be turned on simultaneously while welding; and in the turning and assembly welding of step (4), the variable frequency exciter can be turned on simultaneously while welding to achieve variable vibration edge welding.

[0034] Preferably, the vibration frequency during the welding process and the vibration frequency during the post-weld cooling process are gradually increased to reduce welding porosity, refine the weld seam, and minimize residual stress.

[0035] This invention, through the organic integration of multiple innovative technologies, achieves a manufacturing paradigm upgrade from "experience-driven" to "data-driven" and from "passive correction" to "active control." Its constructed intelligent process chain of "pre-deformation control - welding excitation - phased aging - cyclic bonding - online feedback - precise matching" enables precise stress-shape coordinated control in the manufacturing process of back-mounted hatch covers. This not only significantly reduces reliance on pyrotechnic straightening but also improves key geometric accuracy, solving the technical problem of unstable hatch cover manufacturing quality and providing a replicable and scalable intelligent manufacturing solution for shipbuilding.

[0036] The specific technical effects of this invention are further analyzed as follows: First, the present invention provides a segmented assembly manufacturing process for a back-mounted hatch cover. By employing a combination of "gravity pressure iron + frequency converter" during the segmented welding stage, it achieves immediate overall vibration aging after welding, effectively releasing residual welding stress. This significantly reduces the workload of fire straightening and improves material integrity.

[0037] Secondly, the present invention provides a segmented assembly manufacturing process for a back-mounted hatch cover, in which the vibrator is activated simultaneously during the assembly welding and pyrotechnic correction stages to achieve "simultaneous heating and vibration," thereby enabling the synergistic effect of thermoplastic deformation and dynamic stress relaxation, significantly reducing restraint stress and minimizing subsequent pyrotechnic requirements.

[0038] Third, the segmented assembly manufacturing process of the back-mounted hatch cover of the present invention can reduce the risk of material grain coarsening and toughness reduction caused by excessive fire straightening by reducing the amount of fire straightening work.

[0039] Fourth, the present invention provides a segmented assembly manufacturing process for a back-mounted hatch cover. By employing an intelligent support unit consisting of a servo lifter, a ball joint top block, and an infrared ranging sensor, the reverse deformation amount can be flexibly set during hatch cover welding, and the deformation amount of the hatch cover can be monitored.

[0040] Fifth, the present invention provides a segmented assembly manufacturing process for a back-loaded hatch cover. Through a "five-stage cyclic control strategy," it gradually approaches an ideal flat state under its own weight. Each cycle dynamically adjusts the anti-deformation amount based on measured data, forming a "perception-decision-execution" closed loop. Ultimately, this ensures good control over the flatness of the hatch cover's top / bottom surface, improving the hatch cover's flatness accuracy by more than 50% compared to traditional manufacturing processes. This achieves high-precision geometric forming and ensures the stability of the back-loaded support.

[0041] Sixth, the present invention provides a segmented assembly manufacturing process for a back-mounted hatch cover. All key parameters (anti-deformation amount, vibration frequency, bonding time, etc.) are uniformly set and executed by a central controller, eliminating human error and reducing energy consumption through bonding. The infrared ranging system provides digital recording of the entire process, and the deformation evolution of each segment is traceable and comparable. After the paired hatch covers are manufactured using this process, the standard deviation of their key dimensions is reduced by more than 40%, and the matching error between the support block and the support leg is ≤0.5mm, achieving true "ready to use" and improving the consistency of segmented manufacturing.

[0042] Seventh, the present invention provides a segmented assembly manufacturing process for a back-mounted hatch cover, employing low-frequency vibration during the high-temperature welding period to promote dislocation slippage; medium-frequency vibration during the mid-cooling phase to refine grains; and high-frequency vibration after complete cooling to eliminate microscopic residual stress. This optimizes the distribution of residual stress, improves the structural service life, and significantly enhances fatigue resistance and stress corrosion resistance.

[0043] Eighth, the present invention provides a segmented assembly manufacturing process for a back-loaded hatch cover. The length of the support legs is dynamically adjusted based on the measured height of the support parts during the back-load test to avoid "loose connections" or "overpressure." The guide block and the limiting block adopt a "temporary spot welding + matching welding" process to ensure alignment accuracy and prevent lateral displacement during the back-load process. This enables precise matching of the support structure and ensures back-load safety.

[0044] Ninth, the present invention provides a segmented assembly manufacturing process for a back-mounted hatch cover, which is highly flexible and adaptable: the servo lifting system is programmable and the same set of assembly jigs can be adapted to hatch covers of different specifications; the "five-stage cyclic control" strategy is adaptive and can cope with disturbance factors such as material batch differences and changes in ambient temperature; the vibration isolation pad design effectively blocks external vibration interference and ensures measurement and vibration aging accuracy.

[0045] Tenth, the present invention provides a segmented assembly manufacturing process for a back-mounted hatch cover, which integrates a hydraulic pulsating frequency converter. This converter utilizes the rotational motion of a micro-eccentric column between the main and auxiliary hydraulic chambers to induce hydraulic oil pulsation, thereby driving the lifting column to generate axial micro-vibration. This design achieves a deep integration of vibration excitation and support functions, and has advantages such as high excitation efficiency, good directional consistency, compact structure, stable operation, and low vibration stress relief noise. Attached Figure Description

[0046] Figure 1 This is a schematic diagram of the overall process for manufacturing a segmented assembly of a back-mounted hatch cover according to the present invention. Figure 2 This is a schematic diagram of the hatch cover segment with a pre-designed first anti-deformation arch structure during manufacturing (the top surface of the hatch cover segment in the diagram is facing up and the bottom surface is facing down). Figure 3 This is a schematic diagram of a second anti-deformation arch structure pre-designed during the manufacture of the hatch cover (the top surface of the hatch cover segments in the diagram is facing down and the top surface is facing up). Figure 4 This is a schematic diagram of the upper and lower centering structure of two hatch covers (horizontally movable hatch cover and liftable hatch cover) during the load test; Figure 5 This is a schematic diagram of the load-bearing support structure between two hatch covers (a horizontally movable hatch cover and a retractable hatch cover); Figure 6 This is a schematic diagram showing the usage status of the middle group's tire frame; Figure 7 This is a schematic diagram showing the usage status of the pier assembly frame; Figure 8 yes Figure 7 A schematic diagram of the structure of the lifting pier; Figure 9 yes Figure 7 A schematic diagram of the contour base in the diagram.

[0047] In the diagram: 1. Hatch cover segment; 2. Hatch cover; 3. Middle assembly frame; 4. Ballast; 5. Abutment assembly frame; 6. First anti-deformation arch structure; 7. Working platform; 8. Second anti-deformation arch structure; 9. Assembly base; 10. Lifting abutment; 11. Servo lifter; 12. Ball joint; 13. Lifting column; 14. Ball joint top block; 15. Spring; 16. Through hole; 17. Infrared ranging sensor; 18. 19. Elevation seat, 20. Vibrator, 21. Main hydraulic chamber, 22. Secondary hydraulic chamber, 23. Partition wall, 24. Cylindrical shaft, 25. Micro-eccentric column, 26. Servo motor, 27. Back load support structure, 28. Support block, 29. Support leg, 30. Centering structure, 31. Guide block, 32. Limiting block, 33. Variable frequency vibrator, 34. Magnetic suction plate, 35. Vibration isolation pad, 36. Asbestos pad, 37. Rubber pad, 38. Horse plate. Detailed Implementation

[0048] The specific embodiments of the present invention will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solutions of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0049] like Figures 1 to 9 The illustration shows an embodiment of a segmented assembly manufacturing process for a back-mounted hatch cover according to the present invention, including a segmented hatch cover manufacturing process and a hatch assembly manufacturing process. The segmented hatch cover manufacturing process includes the following steps: (1) Material preparation: Cut materials according to the design drawings. When cutting materials, add corresponding welding shrinkage allowance and fire straightening shrinkage allowance to the main components in the length and width directions of the hatch cover; wherein, the main components include the top plate and reinforcing components, as well as the end plate, side plate and reinforcing components; (2) Segmented assembly and welding: The hatch cover is divided into two segments and manufactured separately. When manufacturing segments, the first group assembly and welding are carried out, and then the middle group assembly and welding are carried out. Among them, the middle group assembly and welding of the hatch cover adopts the reverse construction method with the top plate at the bottom. That is, the top plate of the hatch cover is placed on the middle group jig 3 for positioning and marking. The four corners of the top plate and the middle group jig 3 are limited by the horse plate 37. Then the structural components are installed on the top plate. Note that the bottom plate is not installed yet. After completion, the middle group welding is carried out. When welding the middle group, the intersection area of ​​the cross beam and the longitudinal beam, as well as the four corner areas of the hatch cover, are fixed with pressure iron 4 to reduce the deformation of the top plate. (3) Turning over and fire correction: After the segmented welding of hatch cover section 1 is completed, it is turned over and installed on the pier assembly jig 5 for fire correction; the fire correction adopts the method of line heating and plane correction; the fire correction includes correcting the top plate plane, removing stress from the structural hardening, adjusting the closing seam, adjusting the four corners of the hatch cover to be level, and checking the straightness of the side plates and end plates around the hatch cover. In step (2) segmented welding, the segmented anti-deformation amount of hatch cover segment 1 is set and adjusted by the middle group jig 3 to form a first anti-deformation arch structure 6 in which the hatch cover segment 1 is raised in the middle and droops around the perimeter.

[0050] By setting the first anti-deformation arch structure 6, the hatch cover segment 1 can form a flat structure on the top and bottom surfaces by its own weight after welding and in a free support state.

[0051] In this embodiment, the hatch cover closing process also includes the following steps after the turning and fire correction in step (3): (4) Turning over and welding the assembly: After the hatch cover section 1 is straightened by fire, it is turned over again and installed and positioned on the pier assembly jig 5 for assembly and welding. (5) Installation of bottom plate and box feet: Install the bottom plate and seal it; after the bottom plate is installed and welded, install and weld the box feet; In step (4) of turning over and welding the assembly, the overall anti-deformation amount of the hatch cover 2 is adjusted by the pier assembly jig 5 before welding, so that the hatch cover 2 is a second anti-deformation arch structure 8 with a raised center and a drooping perimeter.

[0052] By setting the second anti-deformation arch structure 8, the hatch cover 2 can form a flat structure on the top and bottom surfaces by its own weight when it is closed, welded and in a free support state.

[0053] As a further improvement of this embodiment, the pier assembly frame 5 includes an assembly base 9 and N lifting piers 10 distributed on the assembly base 9; each lifting pier 10 includes a servo lifter 11 and a ball joint top block 14 rotatably mounted on the top of the lifting column 13 of the servo lifter 11 via a ball joint joint 12; the back of the ball joint top block 14 is provided with a spring 15 that automatically straightens the ball joint top block 14; a through hole 16 is provided at the center of the ball joint top block 14, and an infrared ranging sensor 17 whose detection light can pass through the through hole 16 is provided at the top of the servo lifter 11.

[0054] Preferably, the spring 15 is a disc spring with a central through hole.

[0055] Preferably, the servo lifter 11 is a servo lifting hydraulic cylinder or a servo lifting electric cylinder, which can adjust the lifting height through servo control.

[0056] In this embodiment, the servo lift 11 and the infrared ranging sensor 17 are respectively connected to the controller.

[0057] Preferably, the base 9 of the main assembly is also provided with a number of level seats 18, and ball joint top blocks 14 are rotatably provided on the level seats 18 via ball joint pairs 12; the ball joint top blocks 14 located on the lifting support 10 can be raised or lowered by the servo lifter 11 to be higher or lower than the ball joint top blocks 14 on the level seats 18; the servo lifter 11 is also provided with a vibrator 19 for driving the lifting column 13 of the servo lifter 11 to make up-down micro-vibrations.

[0058] Preferably, the leveling seat 18 is arranged along the two sides and four corners of the hatch cover 2 to simulate the actual support of the hatch cover 2 in use.

[0059] By setting the leveling seat 18, the number of servo lifters 11 can be reduced. On the other hand, when the servo lifters 11 are driven to descend, the hatch cover 2 can sit freely on the ball joint top block 14 of the leveling seat 18, which facilitates the detection of the flatness of the hatch cover 2 in a free support state.

[0060] Preferably, the vibrator 19 includes an auxiliary hydraulic chamber 21 integrally disposed next to the main hydraulic chamber 20 of the servo lift 11, a partition wall 22 disposed between the main hydraulic chamber 20 and the auxiliary hydraulic chamber 21, a cylindrical shaft 23 disposed on the partition wall 22 to separate the main hydraulic chamber 20 and the auxiliary hydraulic chamber 21, a micro-eccentric column 24 disposed on the cylindrical shaft 23, and a servo motor 25 for driving the cylindrical shaft 23 and the micro-eccentric column 24 to rotate together. The eccentric side of the micro-eccentric column 24 can be driven to rotate by the servo motor 25 to alternately enter the main hydraulic chamber 20 and the auxiliary hydraulic chamber 21 to realize the pulsation of hydraulic oil in the main hydraulic chamber 20.

[0061] Preferably, the servo motor 25 is a variable frequency servo motor, thereby making the vibrator 19 a hydraulic pulse variable frequency vibrator.

[0062] In this embodiment, the first anti-deformation arch structure 6 and the second anti-deformation arch structure 8 are both implemented by controlling different lifting amounts of each of the servo lifters 11.

[0063] Preferably, the hatch cover segment manufacturing process further includes the following steps after the bottom sealing plate in step (5): (6) Installation of the back load support structure: The back load support structure 26 includes a support block 27 set on the top surface of one of the horizontally movable hatch covers in a pair of back load hatch covers, and a support leg 28 set on the bottom surface of the other of the liftable hatch covers in a pair of back load hatch covers; the height data of each support part on the bottom surface of the liftable hatch cover is measured using a total station, and the leg length of the support leg 28 with a margin is corrected according to the height data of each support part before being welded to the support part on the bottom surface of the liftable hatch cover; after the support leg 28 on the bottom surface of the liftable hatch cover is installed and welded, the thickness dimension data of the support block 27 on the top surface of the horizontally movable hatch cover is detected and determined by conducting a back load test on a pair of back load hatch covers, and the thickness of the support block 27 with a margin is corrected according to the detected thickness dimension data of the support block 27 before being installed and welded to the support part on the top surface of the horizontally movable hatch cover.

[0064] Preferably, the installation of the back load support structure in step (6) further includes the installation of the centering structure 29, which includes a guide block 30 disposed on the top side of the horizontally movable hatch cover and a limiting block 31 disposed on the bottom side of the liftable hatch cover and adapted to the side of the guide block 30; the limiting block 31 is temporarily spot welded before the back load test and is fully welded during the back load test.

[0065] As a further improvement, in the segmented welding of step (2), the pressure iron 4 used is a gravity pressure iron that is pressed by gravity. It is fixedly connected to the hatch cover segment 1 by spot welding, and a variable frequency vibrator 32 is installed on the pressure iron 4. After the segmented welding is completed, the variable frequency vibrator 32 is turned on. Each variable frequency vibrator 32 uses the same excitation frequency to perform overall vibration aging treatment on the welded hatch cover segment 1.

[0066] Preferably, the variable frequency vibrator 32 is provided with a magnetic suction plate 33, and the variable frequency vibrator 32 is fixed to the pressure iron 4 by the magnetic suction plate 33, which facilitates quick assembly and disassembly. The magnetic suction plate 33 can be a permanent magnet or an electromagnet.

[0067] Preferably, the intermediate tire frame 3 is placed on the working platform 7, and a vibration isolation pad 34 is provided between the intermediate tire frame 3 and the working platform 7.

[0068] Preferably, the vibration isolation pad 34 has a double-layer structure, with an asbestos pad 35 on the upper layer and a rubber pad 36 on the lower layer.

[0069] Preferably, the variable frequency vibrator 32 is an eccentric motor variable frequency vibrator.

[0070] Furthermore, in step (4) of the overturning assembly welding, after the welding is completed, the vibrator 19 on the servo lifter 11 of the pier assembly jig 5 is turned on to perform vibration aging treatment on the hatch cover 2, thereby improving the overall deformation resistance and stability of the hatch cover 2 after welding.

[0071] Furthermore, in step (3) of the fire-working correction, while the fire-working correction is being performed, the vibrator 19 on the servo lifter 11 of the pier assembly frame 5 is simultaneously turned on to achieve simultaneous fire-working correction and vibration aging stress relief.

[0072] As a further improvement to this embodiment, in step (4) of the overturning assembly welding, the vibration aging treatment of the hatch cover 2 after the welding is completed adopts a five-stage cyclic control strategy of "lifting-vibration-self-weight contact-measurement-anti-deformation lifting amount setting"; the five-stage cyclic control strategy of "lifting-vibration-self-weight contact-measurement-anti-deformation lifting amount setting" includes the following process: The first stage of lifting and anti-deformation: set the lifting amount of each servo lifter 11, lift the hatch cover 2 as a whole through the servo lifter 11, so that the hatch cover 2 is disengaged from the ball joint top block 14 on the equal height seat 18, and form a certain amount of anti-deformation correction at the part of the servo lifter 11 supporting the hatch cover 2. The second stage of vibration: turn on the vibrator 19 on the servo lift 11 and perform vibration aging treatment on the hatch cover 2 for a period of time. The third stage of self-weight bonding: After vibration aging treatment, the servo lifter 11 descends until the ball joint top block 14 above it is at the same height as the ball joint top block 14 above the equal height seat 18. Under its own weight, the hatch cover 2 is supported in a free state on each ball joint top block 14 and automatically bonding for a period of time, so that the planar shape of the hatch cover 2 is accurate. The fourth stage of measurement: When the automatic folding time is up, each servo lifter 11 continues to descend to the set value, so that the ball joint top block 14 on it completely disengages from the hatch cover 2, so that the hatch cover 2 sits only on the ball joint top block 14 of the equal height seat 18; after it is in place, the infrared ranging sensor 17 on each servo lifter 11 is activated, and the control system obtains the different sags of the supporting part of the hatch cover 2 under its own weight through the ranging data of each infrared ranging sensor 17, and sets the lifting amount for the next lifting and anti-deformation according to the different sags, and then returns to the first stage of lifting and anti-deformation; The fifth stage anti-deformation lifting amount setting: Based on the measurement results of the fourth stage, the flatness of the hatch cover 2 is evaluated, and then a new anti-deformation lifting amount is set for the first stage of lifting anti-deformation during cyclic control. Through the above five-stage cyclical control strategy, the flatness of the hatch cover 2 is adjusted until it reaches the preset optimal state.

[0073] The optimal state can be an absolute value of the flatness of hatch cover 2, or it can be the improvement effect of hatch cover 2 flatness between two consecutive cycles. For example, when the data difference of hatch cover 2 flatness is less than a certain set value after several cycles, the optimal state is reached.

[0074] As a further improvement to this embodiment, in the segmented welding of step (2), the frequency converter 32 can be turned on simultaneously while welding; and in the turning and assembly welding of step (4), the exciter 19 can be turned on simultaneously while welding, so as to achieve simultaneous vibration and welding.

[0075] Preferably, the vibration frequency during the welding process and the vibration frequency during the post-weld cooling process are gradually increased to reduce welding porosity, refine the weld seam, and minimize residual stress.

[0076] This embodiment achieves a manufacturing paradigm upgrade from "experience-driven" to "data-driven" and from "passive correction" to "active control" through the organic integration of multiple innovative technologies. The intelligent process chain it constructs, which consists of "pre-deformation control - welding excitation - phased aging - cyclic bonding - online feedback - precise matching", enables precise stress-shape coordinated control in the manufacturing process of back-mounted hatch covers. This not only significantly reduces reliance on pyrotechnic straightening but also improves key geometric accuracy, solving the technical problem of unstable hatch cover manufacturing quality and providing a replicable and scalable intelligent manufacturing solution for shipbuilding.

[0077] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A manufacturing process for segmented assembly of a back-mounted hatch cover, characterized in that, This includes the segmented manufacturing process of the hatch cover and the assembly manufacturing process of the hatch cover. The segmented manufacturing process of the hatch cover includes the following steps: (1) Material preparation: Cut materials according to the design drawings. When cutting materials, add corresponding welding shrinkage allowance and fire straightening shrinkage allowance to the main components in the length and width directions of the hatch cover; wherein, the main components include the top plate and reinforcing components, as well as the end plate, side plate and reinforcing components; (2) Segmented assembly and welding: The hatch cover is divided into two segments and manufactured separately. When manufacturing segments, the first group assembly and welding are carried out, and then the middle group assembly and welding are carried out. Among them, the middle group assembly and welding of the hatch cover adopts the reverse construction method with the top plate at the bottom. That is, the top plate of the hatch cover is placed on the middle group jig for positioning and marking. The four corners of the top plate are limited by the jig. Then the structural components are installed on the top plate. Note that the bottom plate is not installed yet. After completion, the middle group welding is carried out. When welding the middle group, the intersection area of ​​the cross beam and the longitudinal beam, as well as the four corner areas of the hatch cover, are fixed with pressure irons to reduce the deformation of the top plate. (3) Turning over and fire correction: After the hatch cover is welded in sections, it is turned over and installed on the pier assembly jig for fire correction; the fire correction adopts the method of line heating and plane correction; the fire correction includes correcting the top plate plane, removing stress from the structural hardening, adjusting the closing joint, adjusting the four corners of the hatch cover to be level, and checking the straightness of the side plates and end plates around the hatch cover. (4) Turning over and welding the assembly: After the hatch cover is fire-corrected, it is turned over again and installed and positioned on the pier assembly jig for assembly and welding. (5) Installation of bottom plate and box feet: Install the bottom plate and seal it; after the bottom plate is installed and welded, install and weld the box feet; In the segmented welding of step (2), the segmented anti-deformation amount of the hatch cover is set and adjusted by the middle group jig to form a first anti-deformation arch structure in which the hatch cover segments are raised in the middle and drooping around the perimeter. In step (4) of turning over and welding the assembly, the overall anti-deformation of the hatch cover is adjusted by the pier assembly jig before welding, so that the hatch cover is a second anti-deformation arch structure with a raised center and a drooping perimeter. The pier assembly frame includes an assembly base and N lifting piers distributed on the assembly base; each lifting pier includes a servo lifter and a ball joint top block rotatably mounted on the top of the lifting column of the servo lifter via a ball joint joint. The back of the ball joint top block is provided with a spring that automatically straightens the ball joint top block; a through hole is provided in the center of the ball joint top block, and an infrared ranging sensor whose detection light can pass through the through hole is provided at the top of the servo lifter.

2. The manufacturing process for a segmented assembly of a back-mounted hatch cover according to claim 1, characterized in that, The base of the main assembly is also provided with a number of level seats, and ball joint top blocks are rotatably mounted on the level seats via ball joint pairs; the ball joint top blocks located on the lifting piers can be raised or lowered by the servo lifter to be higher or lower than the ball joint top blocks on the level seats; the servo lifter is also provided with an exciter for driving the lifting column of the servo lifter to make up-down micro-vibrations.

3. The manufacturing process for a segmented assembly of a back-mounted hatch cover according to claim 1, characterized in that, The second anti-deformation arch structure is achieved by controlling the different lifting amounts of each of the servo lifters.

4. The manufacturing process for a segmented assembly of a back-mounted hatch cover according to claim 1, characterized in that, The hatch cover segment manufacturing process also includes the following steps after the bottom sealing plate in step (5): (6) Installation of the back load support structure: The back load support structure includes a support block set on the top surface of one of the horizontally movable hatch covers in a pair of back load hatch covers, and a support leg set on the bottom surface of the other movable hatch cover in a pair of back load hatch covers; the height data of each support part on the bottom surface of the movable hatch cover is measured using a total station, and the leg length of the support leg with a margin is corrected according to the height data of each support part before being welded to the support part on the bottom surface of the movable hatch cover; after the support leg on the bottom surface of the movable hatch cover is installed and welded, the thickness dimension data of the support block on the top surface of the horizontally movable hatch cover is detected and determined by conducting a back load test on a pair of back load hatch covers, and the thickness of the support block with a margin is corrected according to the detected thickness dimension data of the support block before being installed and welded to the support part on the top surface of the horizontally movable hatch cover.

5. The manufacturing process for a segmented assembly of a back-mounted hatch cover according to claim 1, characterized in that, In step (2) segmented welding, the pressure iron used is a gravity pressure iron that is pressed by gravity. It is fixedly connected to the hatch cover by spot welding, and a variable frequency vibrator is installed on the gravity pressure iron. After the segmented welding is completed, the variable frequency vibrator is turned on. Each variable frequency vibrator uses the same excitation frequency to perform overall vibration aging treatment on the segments of the welded hatch cover.

6. The manufacturing process for a segmented assembly of a back-mounted hatch cover according to claim 4, characterized in that, In step (4) of the overturning assembly welding, after the welding is completed, the vibrator on the servo lifter of the pier assembly jig is turned on to perform vibration aging treatment on the hatch cover, thereby improving the overall deformation resistance and stability of the hatch cover after welding.

7. The manufacturing process for a segmented assembly of a back-mounted hatch cover according to claim 1, characterized in that, In step (3) of turning over and straightening, the vibrator on the servo lifter of the pier assembly frame is turned on simultaneously with the straightening process, so as to realize the stress relief by changing the straightening process and aging the vibration.

8. The manufacturing process for a segmented assembly of a back-mounted hatch cover according to claim 6, characterized in that, In step (4) of the overturning assembly welding, the vibration aging treatment of the hatch cover after the welding is completed adopts a five-stage cyclic control strategy of "lifting-vibration-self-weight bonding-measurement-anti-deformation lifting amount setting"; the five-stage cyclic control strategy of "lifting-vibration-self-weight bonding-measurement-anti-deformation lifting amount setting" includes the following process: The first stage of lifting and anti-deformation: set the lifting amount of each servo lifter, lift the hatch cover as a whole through the servo lifter, so that the hatch cover is disengaged from the ball joint top block on the equal height seat, and form a certain amount of anti-deformation correction at the part of the servo lifter supporting the hatch cover. The second stage of vibration: turn on the vibrator on the servo lift and perform vibration aging treatment on the hatch cover for a period of time. The third stage of self-weight bonding: After vibration aging treatment, the servo lift descends until the ball joint top block above it is at the same height as the ball joint top block above the equal height seat. Under its own weight, the hatch cover is supported in a free state on each ball joint top block and automatically bonded for a period of time, so that the planar shape of the hatch cover is accurate. The fourth stage of measurement: When the automatic folding time is up, each servo lifter continues to descend to the set value, so that the ball joint top block on it is completely disengaged from the hatch cover, so that the hatch cover sits only on the ball joint top block of the equal height seat; after it is in place, the infrared ranging sensors on each servo lifter are activated, and the control system obtains the different sags of the hatch cover support part under its own weight through the ranging data of each infrared ranging sensor, and sets the lifting amount for the next lifting and anti-deformation according to the different sags, and then returns to the first stage of lifting and anti-deformation; The fifth stage anti-deformation lifting amount setting: Based on the measurement results of the fourth stage, the flatness of the hatch cover is evaluated, and then a new anti-deformation lifting amount is set for the first stage of lifting anti-deformation during cyclic control. The above five-stage cyclical control strategy is used until the flatness of the hatch cover reaches the preset optimal state.

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