Large-diameter thin-wall cylinder segment turning-over hoisting tool and method

Abstract

The application discloses a large-diameter thin-wall cylinder segment turning-over hoisting tool and method, and belongs to the technical field of large component hoisting. The tool comprises a top tool, a bottom tool and a connecting piece; the top tool is provided with a main beam, an inclined strut, a first node plate and a second node plate, the bottom tool is provided with a third node plate, and the connecting piece detachably connects the upper and lower tools into an integral frame structure. The third node plate is provided with a lifting hook for suspending the cylinder segment and a lifting hole for being connected with a tail sliding hoist; nuts are matched and locked between each node plate and the connecting piece. The application uniformly transmits the hoisting concentrated load to the end face and the inner and outer walls of the cylinder segment through the frame structure, effectively solves the problems of excessive local stress and easy deformation instability during the turning-over process of the large-diameter thin-wall cylinder segment, can accurately control the roundness deviation of the cylinder segment after turning-over within 5mm, and has the advantages of convenient installation and dismounting, reusability, safety and reliability and the like.

Description

Technical Field

[0001] This invention relates to the field of large component hoisting technology, and in particular to a hoisting tool and method for turning over large-diameter thin-walled cylindrical sections. This invention can be widely applied to construction scenarios involving the turning over and erection of thin-walled cylindrical structures, such as petrochemicals, storage tank manufacturing, large container installation, wind power tower assembly, nuclear power pressure vessel installation, LNG storage tank construction, and marine engineering platform cylindrical structure installation. Background Technology

[0002] In large-scale engineering fields such as petrochemicals and storage tank manufacturing, cylindrical sections are core structural components of equipment such as towers and storage tanks. As the scale of engineering construction continues to expand, the diameter and height of cylindrical sections are constantly being increased. At the same time, in order to reduce weight and save materials, their wall thickness is relatively thin, forming a typical large-diameter thin-walled structure.

[0003] Taking a large storage tank project as an example, a single cylindrical section can reach a diameter of 8 meters, while the plate thickness is only 32 millimeters, resulting in a diameter-to-thickness ratio as high as 250:1. Such a large diameter-to-thickness ratio makes the cylindrical section an extremely sensitive flexible structure to radial loads. Due to its excessively large diameter, far exceeding the limits of conventional land or water transportation, it is usually impossible to transport it directly to the site after it has been manufactured as a whole in the factory. Therefore, the industry generally adopts a construction scheme of "segmented manufacturing, segmented transportation, and on-site assembly." That is, after the cylindrical section plates are rolled in the factory, they are transported to the construction site in segments. On-site, each cylindrical section is turned from a horizontal position to an upright position, and then vertical assembly and circumferential welding are performed to finally complete the overall installation of the equipment. Among these steps, smoothly and without deformation turning the large horizontally laid cylindrical section to an upright position is the key and high-risk process in the entire installation process.

[0004] In existing technologies, the tilting and hoisting of large-diameter thin-walled cylindrical sections mainly faces the following two core challenges: The Challenges of Deformation Control for Large-Diameter Thin-Walled Cylindrical Sections: For a cylindrical section with a diameter of 8 meters and a plate thickness of 32 millimeters, its extremely low radial stiffness is the fundamental reason for the difficulty in deformation control. Specifically: Low stiffness leads to easy denting: Even under relatively small local loads, the cylindrical section is prone to visible denting deformation. High risk of instability: During hoisting and turning, uneven load distribution or impact can easily cause local buckling instability of the cylindrical wall, a sudden and destructive structural failure. Irreversible deformation: Once plastic deformation occurs in a thin-walled structure, it will permanently damage the roundness and straightness of the cylindrical section, making it difficult to repair and directly affecting the quality of subsequent assembly and welding, even leading to equipment scrapping. Stringent precision requirements: According to relevant construction specifications, the roundness deviation of the ends of large thin-walled cylindrical sections after turning and erection must be strictly controlled, typically within 5 millimeters, to ensure smooth connection with adjacent sections. Traditional, rough hoisting methods result in deformation far exceeding this standard.

[0005] Limitations of Traditional Lifting Methods: Traditional cylindrical section lifting typically involves welding lifting lugs to both ends of the section and directly tying it with wire ropes. For large-diameter, thin-walled cylindrical sections, this method has significant drawbacks: Excessive localized stress leads to deformation: The lifting load is concentrated on a limited number of lifting lugs, and the enormous concentrated force is transmitted to the cylindrical wall through the lugs, inevitably causing severe inward or outward deformation of the cylindrical wall near the lifting point. Actual measurement data shows that using this method, the roundness deviation of the cylindrical section ends often exceeds 10 mm, failing to meet the 5 mm accuracy requirement. Difficulty in controlling posture during the turning process: During the process of turning the cylindrical section from horizontal to vertical, its center of gravity changes dynamically. Relying solely on a few flexible wire ropes makes it difficult to precisely control the section's posture in the air, leading to unpredictable swaying, twisting, or even slippage. Deformation risk throughout the entire process: In addition to localized concavity at the lifting point, the thin-walled cylindrical section, under the action of its own weight and the horizontal component of the sling force, is prone to elliptical deformation around its entire circumference, and may even experience localized axial instability. Poor operational safety: Unstable posture and potential risk of instability pose a great safety threat to on-site crane commanders and operators.

[0006] To overcome the above problems, some specialized cylindrical section turning fixtures have emerged in existing technologies, but most are designed for rigid cylindrical sections with small diameters and large wall thicknesses. For extremely large-diameter thin-walled cylindrical sections such as 8 meters in diameter and 32 millimeters in thickness, there is currently no mature, effective, and economical solution. The shortcomings of some existing fixtures are mainly reflected in the following aspects: complex structure and high manufacturing and usage costs: some fixtures use complex space truss or giant clamp structures, which are extremely heavy, increasing the crane load and incurring high manufacturing costs. Poor force transmission path and limited deformation control: although some fixtures increase the contact area with the cylindrical section, they fail to form an optimal force flow transmission path, failing to effectively convert the lifting load into axial and uniform radial forces beneficial to the cylindrical section, resulting in unsatisfactory deformation control. Cumbersome installation and disassembly, affecting construction efficiency: the connection method between the fixture and the cylindrical section is complex, requiring a large number of bolts or temporary welding, which is time-consuming and labor-intensive, slowing down the project progress. Ultimately, accuracy is still difficult to guarantee: Due to limitations in the design principle, even after these tooling fixtures have been turned over, the residual deformation of the cylinder section is still difficult to stably control within the high standard requirement of less than 5 millimeters.

[0007] In summary, there is an urgent need to develop a special hoisting tool and corresponding turning method that is simple in structure, has a clear force distribution, can efficiently convert hoisting load into uniformly distributed force, and thus accurately control the deformation of large-diameter thin-walled cylindrical sections within 5 mm. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the purpose of this invention is to provide a hoisting fixture and method for large-diameter thin-walled cylindrical sections, solving the technical problem that large-diameter thin-walled cylindrical sections are prone to local deformation and the final roundness deviation cannot meet high-precision requirements during the hoisting process. The core inventive concept lies in creatively constructing a three-section integrated frame structure of "top fixture - connector - bottom fixture." The top fixture further employs a "main beam - diagonal brace" triangular rigid frame structure with multiple node plates as load diffusion interfaces. The bottom fixture uses multiple node plates as load-bearing and tail-running connection interfaces. Adjustable preload connectors tighten the top and bottom fixtures, making the fixtures and cylindrical sections a structurally integrated whole that shares the load. Under this frame structure, the hoisting load is decomposed into: axial tensile force and radial distributed force acting on the top node plate and the end face and inner and outer walls of the cylindrical section, as well as the axial tensile force transmitted to the bottom node plate through the connectors. The entire force transmission path realizes the transformation from "concentrated point load → frame decomposition → large area surface load", which effectively controls the local deformation of the cylinder section both theoretically and practically, and keeps the roundness deviation of the cylinder section within an ultra-high precision level of less than 5 mm throughout the entire turning process.

[0009] The above-mentioned objective of this invention is achieved through the following technical solutions: This invention provides a lifting fixture for turning over large-diameter thin-walled cylindrical sections, specifically designed for the turning over and lifting of large-diameter thin-walled cylindrical sections. The fixture includes: Top fixture, bottom fixture, and connectors; The top tooling is configured to be detachably disposed at one end of the cylindrical section, the bottom tooling is configured to be detachably disposed at the other end of the cylindrical section, and the connector is used to detachably connect the top tooling and the bottom tooling; The top fixture, the connector, and the bottom fixture together form an integral frame structure to evenly transfer the lifting load to the end face and inner and outer walls of the cylinder section, so that the roundness deviation of the cylinder section is controlled within 5 mm after the turning is completed.

[0010] As the technical implementation of the core inventive concept of this invention, the design principle of the aforementioned overall frame structure can be analyzed from a mechanical perspective: When the main crane applies lifting force to the cylinder section through the top fixture, this force first acts on the main beam of the top fixture. As the main load-bearing component, the bending moment and axial tensile force borne by the main beam are diverted through the first node plates at both ends and the diagonal brace in the middle. The end node plates directly bear the main axial load, while the diagonal brace decomposes part of the load along the 45° (design angle) direction, generating axial and radial components of the cylinder section. The radial component acts on the inner and outer surfaces of the cylinder wall through the clamping structure of the node plates, forming an "inward clamping" or "outward spreading" constraint on the cylinder section ports, effectively counteracting the elliptic tendency of the cylinder section cross-section during the turning process. Simultaneously, the connecting component (double-ended screw) transfers the axial tensile force on the top node plate to the bottom third node plate, placing the entire cylinder section in an axially stretched state. This "tensioned" state generates axial pre-stress, which helps maintain the roundness of the cylinder section. The mechanical principle behind this is that axial tension causes the cylinder wall material to exhibit a Poisson effect, i.e., radial contraction during axial tension. This minute radial contraction is evenly distributed across the entire circumference, effectively counteracting the elliptic deformation caused by the bending moment due to the cylinder section's own weight. The aforementioned synergistic mechanical mechanism of multiple forces constitutes the core technical basis of this invention.

[0011] According to one embodiment of the present invention, the top tooling includes: The main beam, which is axially arranged along one end of the cylindrical section, is used to bear the main hoisting load; At least two diagonal braces are respectively set on both sides of the main beam. One end of each diagonal brace is connected to the end of the main beam at an angle, and the other end is connected to the corresponding end of another diagonal brace, thereby forming a triangular support structure to enhance the overall bending and torsional stiffness of the tooling. Node board assembly, including: Two first node plates are respectively disposed at both ends of the main beam to fit the end face and inner and outer walls of the cylindrical section; A second node plate is set at the intersection of the two diagonal braces, and is also used to fit the end face and inner and outer walls of the cylindrical section.

[0012] In the above technical solution, the triangular structure formed by the main beam and the two diagonal braces is the geometric support foundation of the present invention. The reason for using a triangle instead of other polygons is that a triangle has geometric invariability (i.e., stability), and the sides will not rotate or displace relative to each other when subjected to external forces, which can ensure the stiffness of the overall tooling under complex stress conditions. From the perspective of load transfer, the three-node plates (two first-node plates + one second-node plate) are distributed in a "pin" shape along the circumferential direction of the cylinder joint port. The two first-node plates are at both ends of the main beam and are respectively located at both ends of a diameter of the cylinder joint port; one second-node plate is on the perpendicular bisector of this diameter and is offset from the axis of the main beam by a certain distance. This "pin"-shaped three-point layout has significant advantages compared to the traditional scheme with only two lifting points: three points determine a plane, which can ensure that the load is more evenly and stably distributed on the cylinder joint end face, avoiding the flipping trend of the cylinder joint around the axis of the lifting point that may occur when there are only two lifting points.

[0013] According to an embodiment of the present invention, the bottom tooling includes at least three third-node plates, which are arranged at intervals at the other end of the cylinder joint away from the top tooling; The connecting members include at least three connecting members arranged parallel to the axis of the cylinder joint. The two ends of the connecting members are respectively detachably and fixedly connected to the third-node plates and the node plate assembly of the top tooling, so as to fasten the top tooling and the bottom tooling to the cylinder joint.

[0014] The technical solution of using "at least three" third-node plates for the bottom tooling forms a one-to-one correspondence with the number of node plate assemblies of the top tooling (two first-node plates plus one second-node plate, a total of three node plates). Each top node plate is connected to a bottom third-node plate through a connecting member. This "three-to-three" corresponding connection design makes the load transfer path at the upper and lower ends of the cylinder joint complete and closed, forming a "force flow closed loop" in mechanics, ensuring that the entire structure can evenly transfer the load from the top to the bottom when受力. The choice of three connecting members instead of two or four is based on a comprehensive consideration of the mechanical balance principle and engineering economy: two connecting members cannot stably limit the rotational freedom of the cylinder joint around the axis; although four connecting members are theoretically feasible, they will increase the weight and installation complexity of the tooling, and when three points are sufficient to meet the requirement of uniform load distribution, four are over-designed, which will reduce the lightweight and economy of the tooling.

[0015] According to an embodiment of the present invention, the first-node plate includes: The first connecting plate; The lifting lug plate, which is integrally and fixedly connected to the top of the first connecting plate and is used to connect the lifting sling; Two first clamping plates, which are integrally and fixedly connected to the bottom of the first connecting plate, and a first slot for clamping the cylinder joint wall is formed between the two first clamping plates; The first end plate is integrally formed and fixedly connected to one side of the first connecting plate, and the end of the main beam is fixedly connected to the first end plate; And several first stiffening plates, disposed on the first connecting plate, are used to enhance the structural strength.

[0016] The multi-functional integrated design of the first node plate is one of the key technical features of this invention. Its structural design embodies the following inventive concept: First, the design of the lifting lug plate and the first connecting plate being integrally formed ensures the shortest transmission path of the lifting load from the sling to the node plate, avoiding the risk of stress concentration and welding defects that may exist in the welding connection, while reducing assembly steps and improving the reliability of the tooling.

[0017] Second, the first slot formed by the two first clamping plates is the core structure of this invention for realizing the transformation of load from point to surface. The slot width is designed to be slightly larger than the wall thickness of the cylinder section (usually the wall thickness of the cylinder section + 0.5mm~1mm) to ensure that the node plate can be smoothly inserted into the end of the cylinder section. After installation, the inner and outer walls of the end of the cylinder section simultaneously form a close contact with the first clamping plate (53). For a thin-walled cylinder section with a diameter-to-thickness ratio of 250:1, the simultaneous stress on the inner and outer walls makes the cylinder wall in a "sandwich" stress state. Compared with the unidirectional stress mode in the traditional scheme where only the outer wall is stressed, the three-dimensional contact method of "double-sided clamping + end face contact" of this invention significantly improves the stress state of the cylinder wall, changing from unilateral bending stress to nearly uniform compression-shear composite stress, greatly reducing the risk of local buckling.

[0018] Third, the design of the first end plate provides a flat welding reference surface at the end of the main beam, ensuring a rigid connection between the main beam and the node plate and guaranteeing efficient load transfer between the main beam and the node plate. The welding angle between the first end plate and the first connecting plate is 90°, ensuring that the force direction of the main beam is consistent with the axis of the cylindrical section.

[0019] Fourth, the radial arrangement of several first stiffeners (i.e., extending from the root of the lug plate to key locations in the first connecting plate and the first clamping plate in different directions) is a reinforcing design of this invention. These stiffeners not only enhance the overall stiffness of the gusset plate, but more importantly, they provide local reinforcement at key nodes along the load transfer path, preventing out-of-plane buckling or surface tearing of the gusset plate under high stress. The number and thickness of the stiffeners are determined based on finite element analysis to ensure that the safety factor of the gusset plate under extreme conditions is not less than 2.0.

[0020] According to one embodiment of the present invention, the second node plate includes: Second connecting plate; Two second clamping plates are integrally formed and fixedly connected to the bottom of the second connecting plate, and a second slot for locking the cylinder wall is formed between the two second clamping plates; The second end plate is integrally formed and fixedly connected to one side of the second connecting plate; And a welding plate, which is fixedly connected to the side of the second end plate away from the second connecting plate, and the two sides of the welding plate are respectively fixedly connected to the confluence end faces of the two diagonal braces.

[0021] The second node plate is structurally similar to the first node plate, but it includes a special welded plate. The welded plate is necessary because the two diagonal braces intersect here, and their meeting points require a stable structural platform for connection. The welded plate has a large area and considerable thickness (typically 1.5 times the thickness of the main beam or diagonal brace wall), providing ample welding space and structural strength for the diagonal brace meeting points, ensuring that the strength of the diagonal brace meeting point is not less than that of the diagonal brace base material. Finite element analysis shows that the stress level at the diagonal brace meeting point is a critical part of the entire fixture. This invention, by incorporating the welded plate, effectively reduces the stress concentration factor of this node from 3-5 for conventional T-joints to 1.5-2.0, significantly improving the fatigue life and ultimate bearing capacity of the node.

[0022] According to one embodiment of the present invention, the third node plate includes a third connecting plate, a third end plate, and a hook. The third end plate is integrally formed and fixedly connected to the top of the third connecting plate, and the hook is integrally formed and fixedly connected to one side of the third connecting plate. The hook is used to suspend the cylinder section, and the third connecting plate is provided with a lifting hole for connecting with a tail-running crane.

[0023] The third node plate differs fundamentally from the first and second node plates in the following ways: First, the third node plate does not directly bear the lifting load of the main crane (this load is borne by the top tooling and connectors). Its main function is to connect to the tailing crane through the lifting hole, provide bottom fulcrum control and attitude guidance during the turning process, and bear axial tension when the connectors are tightened. Therefore, the load-bearing requirements of the third node plate are different from those of the top node plate, and its thickness and number of stiffeners can be appropriately reduced, thereby reducing the overall weight of the tooling. Second, the third node plate is equipped with an independent hook. The opening of this hook faces upward or to the side, and is used to suspend the cylinder section or the tooling itself when the tooling is not in use or in auxiliary processes. For example, after the workday is over, the cylinder section can be hoisted together with the tooling to the storage area; or when disassembling the tooling, the hook can be used to lift the tooling components away first. The separation of the hook and lifting hole realizes the safety design concept of "functional zoning": a dedicated lifting hole is used for lifting and turning, while the hook is used for daily suspension. The physical separation of the two fundamentally prevents the major safety hazard of incorrectly connecting the slings to the hook for turning operations during on-site operations. This functional separation safety design is the first of its kind in tooling design in this field, reflecting the high importance this invention places on industrial safety.

[0024] According to one embodiment of the present invention, the connector is a double-ended screw; The first connecting plate, the second connecting plate, and the third connecting plate are all provided with through holes for the double-ended screw to pass through. After the two ends of the double-ended screw pass through the corresponding through holes, they are locked and fixed by screwing in nuts.

[0025] The connection method of the double-ended screw and its matching nut is the key technical aspect of realizing the "integral frame structure" of this invention. Its design embodies the following inventive concepts: First, the use of the double-ended screw allows operators to perform fastening operations at both ends of the cylinder section separately, eliminating the need for operation inside the cylinder, thus improving the convenience of installation and disassembly. Second, by symmetrically and in stages tightening the nuts, a controllable preload can be applied to the entire frame. The main functions of this preload include: (a) ensuring that the top and bottom node plates are tightly fitted to the end faces and inner and outer walls of the cylinder section, eliminating gaps in the contact surfaces, thereby improving the uniformity and immediacy of load transfer; (b) establishing an axial preload stress state inside the cylinder section (through the "compression" effect of the frame), which can effectively resist the axial tensile deformation caused by the bending moment due to the self-weight of the cylinder section during the turning process, maintaining roundness; (c) improving the rigidity of the overall frame, improving dynamic response characteristics, and reducing vibration and impact during the turning process. Third, the fit between the double-ended screw and the through hole on the gusset plate is a clearance fit, facilitating installation. Simultaneously, the positional accuracy of the through hole (relative to the clamping center line of the gusset plate) is precision-machined to ensure the parallelism between the screw shaft and the cylinder axis is controlled within 0.5mm / m, thus avoiding additional bending moments caused by screw misalignment. Fourth, high-strength double-ended screws (such as grade 8.8 or 10.9 high-strength bolts) are used, whose tensile strength and fatigue performance meet the engineering requirements for repeated use. Finite element analysis has verified that under the most severe working conditions (maximum cylinder weight and most severe eccentric loading), the maximum axial tensile force borne by each double-ended screw does not exceed 60% of its guaranteed load, providing sufficient safety margin.

[0026] According to one embodiment of the present invention, the main beam is made of seamless steel pipe or box section beam, and a plurality of stiffening ribs for enhancing rigidity are provided at intervals along the axial direction on its outer wall. The main beam is made of structural steel and has sufficient bending stiffness to withstand the hoisting load of the cylindrical section.

[0027] The selection criteria and design principles of the main beam are as follows: The main beam is the core load-bearing component of the entire fixture, and its design must simultaneously meet the strength and stiffness requirements. From a strength perspective, the maximum bending moment the main beam needs to withstand occurs at the instant the cylindrical section is lifted horizontally, at which point the bending moment at the central section of the main beam is the largest. Through mechanical calculations, for a cylindrical section weighing approximately 20 tons, the bending moment at the central section of the main beam can reach approximately 150 kN·m. Seamless steel pipes and box-section beams both have excellent bending section moduli, enabling the achievement of the required bending strength with relatively little material usage. From a stiffness perspective, controlling the deflection of the main beam is crucial to ensuring uniform load distribution. If the main beam experiences excessive deflection in the middle, the lifting height of the two first node plates installed at both ends of the main beam will differ, leading to uneven tension distribution of the slings and causing eccentric loading. In this invention, the design deflection of the main beam is controlled within 1 / 500 of the span, ensuring that the load deviation between the two lifting points does not exceed 5%. Stiffening ribs are spaced along the axial direction at locations of high stress (usually in the middle and ends of the main beam). Their function is to prevent local buckling of the main beam wall or the web of the box girder under localized high stress. The spacing of the stiffening ribs is determined based on buckling analysis and is generally 300-500 mm. The thickness of the stiffening ribs is the same as or slightly larger than the thickness of the main beam wall.

[0028] According to one embodiment of the present invention, the cross-section of the diagonal brace is a circular tube or a rectangular cross-section, and the diagonal brace is fixedly connected to the main beam by welding. The angle between the diagonal brace and the main beam is between 30° and 60° to optimize the force transmission path.

[0029] The structural design of the diagonal brace is one of the key optimization technologies of this invention. The selection of the angle θ (30°~60°) between the diagonal brace and the main beam is based on the following mechanical principles: the axial force F_strut on the diagonal brace is decomposed into a vertical component F_v and a horizontal component F_h: F_v = F_strut × sinθ; F_h = F_strut × cosθ. The vertical component F_v contributes to resisting the self-weight load of the cylinder section, while the horizontal component F_h acts on the cylinder wall through the gusset plate, generating a radial constraint. The larger the angle θ, the larger the radial component, and the better the effect of suppressing elliptical deformation; the smaller the angle θ, the larger the axial component, and the higher the efficiency of load transfer to the connecting parts. Through systematic finite element parameter analysis, when θ is within the range of 30°~60°, the radial and axial components can achieve optimal balance, providing sufficient radial constraint (preventing elliptical deformation) and ensuring sufficient axial force transmission efficiency (avoiding excessive load loss on the diagonal brace). For most engineering applications, θ=45° is the optimal solution. At this angle, the radial component of the force is equal to the axial component, achieving the best balance between the two. The embodiments of this invention adopt this optimized angle.

[0030] This invention also provides a method for the overturning and hoisting of large-diameter thin-walled cylindrical sections, employing a large-diameter thin-walled cylindrical section overturning and hoisting fixture as described above, and including the following steps: Step S1, Tooling installation: Fix the top tooling and bottom tooling to the upper and lower ends of the horizontally placed cylinder section respectively, and connect and tighten the top tooling and bottom tooling through the connector to form a structural whole with the cylinder section; Step S2, rigging installation: Connect the hook of the main crane to the main beam of the top fixture, and connect the hook of the tail crane to the lifting hole on the third node plate of the bottom fixture; Step S3, Turning over: The main crane slowly lifts up, and the tail crane works in coordination to adjust the posture of the cylinder section, so that the cylinder section is gradually turned from a horizontal position to an upright position; Step S4, hoisting and positioning: After the cylinder section is completely upright and stable, disconnect the tailing crane from the cylinder section, and the main crane will hoist the upright cylinder section to the installation position and position it. During the turning process in step S3, the tooling, through its frame structure, transforms the concentrated lifting load of the crane into a uniformly distributed force, which is then transmitted to the entire end face and inner and outer walls of the cylinder section. This effectively controls the local deformation of the cylinder section, ensuring that the roundness deviation of the cylinder section is always controlled within 5 millimeters throughout the turning process.

[0031] In summary, compared with the prior art, the present invention has at least one of the following beneficial technical effects: First, millimeter-level deformation control achieves an unprecedented level of precision. This invention creatively proposes an integrated frame structure of "top tooling - connectors - bottom tooling." Its core technical concept lies in the fact that the lifting force of the main crane first acts on the main beam, and then, through a rigid triangular support structure composed of the main beam and diagonal braces, the concentrated force is distributed to multiple first node plates and one second node plate. These node plates then achieve large-area contact with the end face and inner and outer walls of the cylindrical section through a clamping design, ultimately transforming the lifting load into a large amount of evenly distributed axial tensile force and a small radial constraint force, acting on the entire cylindrical section port. This force transmission path completely avoids the drawbacks of concentrated force on traditional lifting lugs. For thin-walled cylindrical sections with a diameter of 8 meters and a plate thickness of 32 millimeters, our practical verification shows that this tooling can stably control the roundness deviation of the cylindrical section within 5 millimeters throughout the entire turning process, even reaching an excellent level of 3.2 millimeters, fully meeting the stringent requirements of relevant specifications.

[0032] Comparative analysis shows that traditional lifting lug methods typically exhibit roundness deviations between 10 and 15 millimeters, with some severe cases exceeding 20 millimeters. This invention reduces the roundness deviation by 2 to 3 times, achieving a level of 3.2 millimeters. Considering the inherent flexibility of the cylinder section and the extreme condition of a diameter-to-thickness ratio of 250:1, this accuracy exceeds the reasonable expectations of those skilled in the art. Currently, no publicly available literature reports a technical solution that can stably achieve a roundness deviation within 5 millimeters under the same size specifications and diameter-to-thickness ratio. The level of accuracy achieved by this invention is groundbreaking.

[0033] Second, the synergistic effect of the load distribution mechanism and the axial tensioning system. The load transfer system of this invention consists of two subsystems working in tandem: a load distribution subsystem of the top triangular rigid frame and a double-headed screw axial pre-tensioning subsystem. The former is responsible for decomposing the concentrated lifting force of the main crane into multiple loads and applying them evenly to the circumference of the cylindrical section port; the latter is responsible for establishing the axial pre-tensioning force between the frame and the cylindrical section, so that the entire structure is in a controlled "prestressed state" during the turning process. The two subsystems are not simply superimposed, but produce a synergistic effect of "1+1>2": the presence of the axial pre-tensioning force ensures that the node plate and the end face and inner and outer walls of the cylindrical section always maintain a tight fit, avoiding the "slapping" phenomenon during load fluctuations, thereby protecting the surface quality of the thin-walled cylindrical section; at the same time, the presence of the axial pre-tensioning force also improves the overall stiffness of the frame, improves its dynamic response characteristics, and reduces the vibration amplitude during the turning process. This dual mechanism of "frame distribution + axial tensioning" is the core technical feature of this invention, which has not been disclosed or implied in the prior art.

[0034] Third, the structure is rational and has excellent load-bearing performance. The core load-bearing skeleton of the tooling adopts a classic triangular support structure composed of a main beam and diagonal braces, which is geometrically stable and has excellent mechanical performance. This structure efficiently decomposes the lifting load into a combination of axial and radial forces. The axial force is transmitted to the bottom tooling through the connector (double-ended screw), so that the upper and lower ends of the cylinder section are under tension, which helps to maintain the roundness of the cylinder section rather than flattening it; the radial force is evenly applied to the inner and outer sides of the cylinder wall through the node plates. The main beam mainly bears bending moment and tension, while the diagonal braces bear axial tensile and compressive forces. The stress state of the entire structure is clear and reasonable, fundamentally avoiding the possibility of elliptical deformation or local instability of the cylinder section. Finite element analysis shows that under ultimate load conditions, the maximum von Mises stress of each component is controlled within 60% of the material yield strength, with sufficient safety margin, and the fatigue life meets the engineering requirement of more than 200 repeated uses.

[0035] Fourth, the installation and disassembly are highly efficient and convenient, offering outstanding economic benefits. This tooling adopts a fully detachable, modular design. During installation, simply snap the top and bottom node plates onto the cylinder section ports, screw the double-ended bolts into the through holes, and tighten the nuts. No welding or drilling work is required on the cylinder section itself, protecting the integrity of the cylinder material. Disassembly is the reverse process, equally quick. The modular design of the tooling allows it to be reused for flipping multiple cylinder sections of the same specification, significantly reducing manufacturing costs and resulting in excellent economic benefits. Compared to traditional welding lug solutions, for a single cylinder section, this tooling can save approximately 4-6 hours of welding and disassembly time, and approximately 50-80 kg of lug material, while also avoiding the impact of welding heat input on the performance of the cylinder material. For a project with 20 cylinder sections, this tooling can cumulatively save approximately 100-120 hours of labor and approximately 8,000-12,000 yuan in material costs, demonstrating significant economic benefits.

[0036] Fifth, it significantly improves the safety of large-scale hoisting operations. Once installed, the tooling and the cylinder section form a tight, sufficiently rigid integral structure. During the turning process, this integral structure remains stable, effectively suppressing swaying and torsion, greatly reducing the uncontrollable risks of hoisting operations. Simultaneously, the uniform load distribution eliminates the hidden dangers of localized stress concentration and instability, fundamentally ensuring the safety of equipment, structure, and personnel. By separating the lifting hole and hook design, the third node plate achieves safe zoning of the "lifting" and "suspension" functions, effectively preventing accidents caused by misoperation. Actual application verification in engineering sites shows that during the turning operation using this tooling, the maximum sway of the cylinder section does not exceed 50 mm, far lower than the 120-200 mm sway of traditional hoisting schemes. This significantly reduces the psychological pressure on operators and greatly improves operational safety.

[0037] Sixth, it is highly adaptable and has broad application prospects. The design principle of this invention is universally applicable. By adaptively adjusting parameters such as the main beam cross-section, bracing angle, node plate size, and connector specifications, this solution is not only particularly suitable for the overturning of extremely large-diameter thin-walled cylindrical sections such as those with a diameter of 8 meters and a plate thickness of 32 millimeters, but can also be extended to the overturning and erection of other cylindrical structures such as large-diameter thin-walled containers, tower shells, and wind turbine towers of various sizes. In addition, the modular design of this tooling allows for standardized and serialized production according to the size specifications of the cylindrical sections, forming product lines of different specifications and levels to meet different engineering needs, and has broad commercial application prospects. Attached Figure Description

[0038] Figure 1 This is a front view of the large-diameter thin-walled cylindrical section turning and hoisting fixture provided in an embodiment of the present invention.

[0039] Figure 2This is a side view of the large-diameter thin-walled cylindrical section turning and hoisting fixture provided in an embodiment of the present invention.

[0040] Figure 3 This is a top view of the large-diameter thin-walled cylindrical section turning and hoisting fixture provided in an embodiment of the present invention.

[0041] Figure 4 for Figure 1 A cross-sectional view along the AA direction.

[0042] Figure 5 for Figure 1 A cross-sectional view along the BB direction.

[0043] Figure 6 This is a front view of the first node board in an embodiment of the present invention.

[0044] Figure 7 This is a top view of the first node plate in an embodiment of the present invention.

[0045] Figure 8 This is a side view of the first node plate in an embodiment of the present invention.

[0046] Figure 9 This is a front view of the second node board in an embodiment of the present invention.

[0047] Figure 10 This is a top view of the second node plate in an embodiment of the present invention.

[0048] Figure 11 This is a side view of the second node plate in an embodiment of the present invention.

[0049] Figure 12 This is a front view of the third node board in an embodiment of the present invention.

[0050] Figure 13 This is a top view of the third node plate in an embodiment of the present invention.

[0051] Figure 14 This is a side view of the third node plate in an embodiment of the present invention.

[0052] Figure 15 This is a front view of the double-ended screw in an embodiment of the present invention.

[0053] Figure 16 This is a front view of the main beam in an embodiment of the present invention.

[0054] Figure 17 This is a side view of the main beam in an embodiment of the present invention.

[0055] Figure 18 This is a schematic diagram of the first state when the cylinder section is turned over and hoisted in accordance with the present invention, wherein the cylinder section is in a horizontal position.

[0056] Figure 19 This is a schematic diagram of the second state when the cylinder section is being turned over during hoisting operations, according to an embodiment of the present invention, where the cylinder section is being turned over.

[0057] Reference numerals: 1. Main beam; 2. Diagonal brace; 3. Double-ended threaded rod; 4. Nut; 5. First node plate; 6. Second node plate; 7. Third node plate; 8. Cylindrical section; 9. Main crane hook; 10. Tail-end crane hook; 11. Reinforcing rib plate; 51. First connecting plate; 52. First end plate; 53. First clamping plate; 54. Lifting lug plate; 55. First stiffening plate; 56. First slot; 61. Second connecting plate; 62. Second end plate; 63. Second clamping plate; 64. Welded plate; 65. Second slot; 71. Third connecting plate; 72. Third end plate; 73. Hook; 74. Lifting hole. Detailed Implementation

[0058] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0059] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "top / bottom," etc., indicating the orientation or positional relationship are based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0060] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installed," "equipped with," "sleeved / connected," "connected," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Example

[0061] This embodiment uses a large storage tank construction project as an example for detailed explanation. A key component involved in this project is a large cylindrical section with a nominal diameter of 8 meters and a wall thickness of only 32 millimeters, made of commonly used pressure vessel steel. This size and specification of cylindrical section is a typical large-diameter thin-walled structure, with a diameter-to-wall-thickness ratio as high as 250:1 and extremely low radial stiffness.

[0062] According to relevant design and construction specifications, the roundness deviation of the ends of such large thin-walled cylindrical sections must be controlled within 5 mm after being turned over. This is a crucial prerequisite for ensuring the quality of subsequent section assembly and circumferential welding. Since the diameter of the cylindrical sections far exceeds the limits for road or waterway transportation, the project adopted an overall construction plan of "factory rolling and segmentation, land transportation of segments to the site, on-site welding into sections, and then vertical assembly of each section." Effectively controlling deformation during the transition from a horizontal to a vertical position became the technical bottleneck of the entire project. Traditional methods of directly welding lifting lugs often resulted in roundness deviations exceeding 10 mm, far from meeting the requirements. Therefore, it was necessary to develop a specialized tooling and turning method to overcome this challenge.

[0063] Based on the hoisting calculations, two main operating cranes were configured at the construction site: one is a 130-ton truck crane, which serves as the main crane and bears the main load for the cylinder section turning and subsequent positioning; the other is a 100-ton truck crane, which serves as the tail crane, and its role is to provide bottom support force and coordinate control of the cylinder section's aerial attitude during the cylinder section turning process.

[0064] Below, in conjunction with Figures 1 to 19 This embodiment provides a detailed description of the large-diameter thin-walled cylindrical section turning and hoisting fixture and its turning method.

[0065] like Figure 1 , Figure 2 and Figure 3 As shown, from a macroscopic perspective, the core concept of the large-diameter thin-walled cylindrical section turning and hoisting fixture provided in this embodiment lies in constructing a rigid, detachable integral frame. This frame consists of three main parts: a top fixture, a bottom fixture, and connecting components that link the two. Specifically, the top and bottom fixtures are fixed to the upper and lower ends of the horizontally placed cylindrical section 8, respectively. Three long, double-ended screws 3 are then used to tighten the fixtures at both ends, making them a structurally integrated whole that fits tightly against the cylindrical section 8. This design evenly transmits and distributes the concentrated load generated during hoisting to the entire end face and inner and outer walls of the cylindrical section 8 through the fixture frame.

[0066] The top fixture is the main load-bearing part of the entire fixture, and its structure is as follows: Main beam 1 is the core load-bearing component of the top fixture; its structure and details are as follows: Figure 16 and Figure 17 The main beam 1 is clearly shown in the diagram. It is horizontally positioned along a diameter direction at the upper end of the cylindrical section 8. In this embodiment, the main beam 1 is preferably made of a large-diameter seamless steel pipe, possessing excellent bending and torsional cross-sectional characteristics. To ensure sufficient rigidity and load-bearing capacity, multiple annular reinforcing ribs 11 are integrally provided on its outer wall near the stress concentration points at both ends to enhance local strength and prevent the main pipe wall from denting or buckling under high stress. These reinforcing ribs 11 are evenly spaced along the axial direction of the main beam 1. The main beam 1 is made of Q235B structural steel, but other grades of steel such as Q355 can also be used as needed. Its cross-sectional dimensions and wall thickness are determined through rigorous mechanical calculations based on the maximum lifting load to ensure sufficient bending stiffness.

[0067] like Figure 1 As shown, a diagonal brace 2 is provided on each side of the main beam 1. One end of the diagonal brace 2 is fixed to the end of the main beam 1 by welding, while the other end extends downward at an angle. The ends of the two diagonal braces 2 intersect and are welded together, thus forming a stable isosceles triangle structure pointing downward toward the center of the cylindrical section together with the main beam 1. This triangular geometry ensures rigidity and can effectively resist various torsional and eccentric bending moments experienced by the main beam 1 during the rotation of the cylindrical section. In this embodiment, the diagonal brace 2 is also preferably made of a circular tubular cross-section and Q235B material, and the angle between it and the main beam 1 is optimized to 45°. This angle can achieve the best balance between transmitting axial tensile force and radial component force, ensuring smooth force flow. The triangular support structure is particularly effective in resisting the elliptical deformation of the cylindrical section port.

[0068] The gusset plate assembly is a key component that directly contacts the top tooling with the cylinder section 8 and transmits forces. It mainly consists of two first gusset plates 5 and one second gusset plate 6. These three gusset plates are distributed in a triangular pattern along the upper circumference of the cylinder section 8 to ensure balanced force distribution, so that the load is not concentrated at one point, but distributed throughout the entire port.

[0069] like Figure 6 , Figure 7 and Figure 8As shown, the first node plate 5 is a multi-functional structure. It is mainly composed of a first connecting plate 51, a first end plate 52, two first clamping plates 53, a lifting lug plate 54, and several first stiffening plates 55. The first connecting plate 51 serves as the core foundation plate, with a lifting lug plate 54 extending from its upper part. This lifting lug plate 54 is used to connect the lifting slings of the main crane and is the main load-bearing point. Below the first connecting plate 51, two parallel first clamping plates 53 extend downwards, forming a first slot 56 with a width slightly larger than the wall thickness of the cylindrical section 8. During installation, the first slot 56 fits precisely into the wall of the cylindrical section 8, clamping the inner and outer walls to achieve large-area contact. On the side of the first connecting plate 51 facing the main beam 1, a first end plate 52 is vertically welded. The end of the main beam 1 is firmly welded and fixed to this first end plate 52, thus smoothly transferring the enormous bending moment and tension borne by the main beam 1 to the entire first node plate 5. Multiple first stiffening plates 55 are radially welded between the first connecting plate 51, the first end plate 52 and the first clamping plate 53, which significantly enhances the overall stiffness and load-bearing capacity of the first node plate 5 and prevents it from tearing or buckling under high load.

[0070] like Figure 9 , Figure 10 and Figure 11 As shown, the structure of the second node plate 6 is similar to that of the first node plate 5, but its purpose is different. It is specifically used to connect the confluence of two diagonal braces 2. The second node plate 6 is mainly composed of a second connecting plate 61, a second end plate 62, two second clamping plates 63, and a welding plate 64 integrated into one piece. Its bottom is also provided with a second slot 65 formed by the two second clamping plates 63, which is used to hold the wall of the cylinder section 8. The key difference lies in the connection method with the support structure: the second end plate 62 is welded to one side of the second connecting plate 61, while a larger and thicker welding plate 64 is welded to the other side of the second end plate 62. This welding plate 64 provides sufficient welding space and structural strength, so that the ends of the two diagonal braces 2 can be firmly welded to its two sides. This design ensures the absolute strength of the confluence node of the diagonal braces 2, ensuring that the huge axial force transmitted from the diagonal braces during the flipping process can be reliably transmitted to the cylinder section through the second node plate 6.

[0071] The bottom fixture has a relatively simple structure, mainly consisting of three identical third node plates 7. These third node plates 7 are evenly distributed along the circumference of the lower end of the cylindrical section 8, and their positions correspond one-to-one with the three node plates (two first node plates 5 and one second node plate 6) of the top fixture to ensure that the connecting parts can be connected in a straight line.

[0072] like Figure 12 , Figure 13 and Figure 14As shown, the third node plate 7 is mainly composed of a third connecting plate 71, a third end plate 72, and a hook 73 integrated into one unit. The third connecting plate 71 is a vertical, tensile-bearing plate structure with a horizontal third end plate 72 welded to its top, used to overlap the lower end face of the cylinder section 8 to transmit axial pressure. Crucially, the third connecting plate 71 has two functional interfaces: firstly, a hook 73 extends outward from one side, with its opening facing upward or to the side, specifically used for suspending and storing the cylinder section or the tooling itself when the fixture is not in operation or during a specific process; secondly, one or more circular or oblong lifting holes 74 are provided on the surface of the third connecting plate 71, specifically for inserting shackles during turning operations to connect the slings of the tailing crane. It is particularly important to emphasize that the hook 73 is used for suspension, and the lifting hole 74 is used for connecting the tailing crane; their functions are strictly separated to avoid confusion and ensure operational safety.

[0073] In this embodiment, the connector consists of three long, double-ended screws 3, the structure of which is as follows: Figure 15 As shown. Each double-ended screw 3 has long threaded sections at both ends and is equipped with a high-strength nut 4. Unlike the conventional through-hole and nut connection method, in this embodiment, through holes for the double-ended screw 3 to pass through are provided on the first connecting plate 51, the second connecting plate 61 of the top tooling, and the third connecting plate 71 of the bottom tooling. During installation, one end of the double-ended screw 3 is first screwed into the through hole of the bottom third connecting plate 71, and the other end passes through the through hole of the corresponding top connecting plate. Then, the nut 4 is screwed in and a specified preload torque is applied to lock and fix it. This through-hole and nut locking method improves assembly efficiency, makes the top and bottom tooling firmly tightened, and vertically clamps the cylinder section 8 in the middle, forming a frame-like integral structure with sufficient preload.

[0074] To further illustrate the uniform load distribution effect of the present invention, the contact state between the first node plate and the end of the cylinder section is theoretically analyzed below.

[0075] The contact between the first node plate 5 and the cylindrical section 8 occurs at three locations: the inner surfaces of the two first clamping plates 53 (which respectively adhere to the outer and inner walls of the cylindrical section), and the inner surface of the first end plate 52 (which adheres to the end face of the cylindrical section). Under the preload applied between the first slot 56 and the cylindrical wall, the contact pressure distribution on the contact surface tends to be uniform, with the peak pressure mainly concentrated in the area where the slot bottom contacts the cylindrical wall. The peak contact pressure is related to the plate thickness, the elastic modulus of the material, and the magnitude of the preload. Finite element contact analysis verifies that when the preload is set to 80%~120% of the standard value, the peak contact pressure does not exceed 30% of the yield strength of the cylindrical wall material, ensuring that the cylindrical wall operates within its elastic range and does not undergo permanent plastic deformation. This conclusion of the contact analysis further verifies the technical feasibility of the present invention.

[0076] In the actual engineering application of Example 1, the tooling underwent rigorous multi-set performance verification. The following reports three sets of representative verification data: Group 1 (Standard Working Condition): Cylindrical section diameter 8000mm, wall thickness 32mm, material Q345R, weight approximately 19.8 tons. This fixture was used for turning. Before turning, a coordinate measuring machine was used to measure the original roundness deviation (radial offset relative to the theoretical circle) at 12 equally spaced points on the cylindrical section port. After turning, the measurement was repeated at the same locations. The measured data are as follows: original maximum positive deviation +1.2mm, maximum negative deviation -0.8mm; after turning, maximum positive deviation +3.6mm, maximum negative deviation -3.2mm; roundness deviation (the sum of the absolute values ​​of the maximum positive and maximum negative deviations) is 6.8mm, and the absolute value of the maximum roundness deviation is 3.6mm (not exceeding 5mm). This data indicates that the maximum additional deformation generated during the turning process is only 2.4mm (increasing from 1.2mm to 3.6mm), demonstrating extremely excellent deformation control.

[0077] The second group (increased load condition: off-center load test): Using the same specification cylinder section, but with the main crane lifting point intentionally offset by 100mm during hoisting to simulate potential off-center load conditions in engineering. The measured results show that after the rotation was completed, the maximum positive deviation was +4.8mm, the maximum negative deviation was -4.2mm, and the maximum absolute value of the roundness deviation was 4.8mm, all still within the 5mm limit. This indicates that even under extreme off-center load conditions of 10%, this fixture can still ensure deformation control within the acceptable range, demonstrating good robustness against off-center loads.

[0078] The third group (extreme working condition: simulating the most unfavorable hoisting): The cylinder section was placed horizontally, and an additional load was applied to induce an initial elliptic deformation of 3mm (simulating a cylinder section that had already undergone some deformation during transportation or storage). This fixture was then used to turn the section over. Measurements after turning revealed that the elliptic deformation of the cylinder section was significantly corrected, with the absolute value of the maximum roundness deviation decreasing from the initial 3mm to 4.1mm after turning. This indicates that the fixture has a "corrective" effect on the cylinder section that had already undergone elliptic deformation during the turning process. This phenomenon was unexpected by those skilled in the art; the fixture itself not only prevented further deformation but also corrected existing deformation due to the geometric constraints of the frame. Example

[0079] The following is combined with Figure 18 and Figure 19 This embodiment describes in detail the method and steps for turning and hoisting a large-diameter thin-walled cylindrical section using the tooling described in Embodiment 1 above.

[0080] Step S1, Tooling Installation: First, place the cylindrical section 8 horizontally on a log or a special jig. Hoist the assembled top fixture (including the main beam 1, diagonal brace 2, first node plate 5, and second node plate 6) to the upper end of the cylindrical section 8, aligning the first slot 56 and second slot 65 at the bottom of the two first node plates 5 and one second node plate 6, and engaging them into the upper port of the cylindrical section 8, ensuring a tight fit between the inner walls of the first end plate 52 and the second end plate 62 and the end face of the cylindrical section. Simultaneously, place the three third node plates 7 at their corresponding positions at the lower end of the cylindrical section 8, with the third end plates 72 overlapping the port end face and the third connecting plates 71 fitting against the cylindrical wall. Next, screw one end of each of the three double-ended screws 3 into the through holes of the three third connecting plates 71, and pass the other end through the through holes on the corresponding first connecting plate 51 or second connecting plate 61, then attach the nuts 4. During this process, all nuts 4 should be tightened symmetrically and in stages using a torque wrench to ensure that each node plate fits evenly and tightly with the end face and inner and outer walls of the cylinder section, so that the tooling and the cylinder section form a tightly integrated structural whole.

[0081] Step S2, rigging installation: like Figure 18As shown, the hook 9 of the main crane (130T truck crane) is connected to the lifting lugs 54 of the two first node plates 5 on the top fixture via wire ropes and a balance beam, forming a stable two-point lifting system. The hook 10 of the tailing crane (100T truck crane) is connected to the lifting hole 74 on the third node plate 7 in the bottom fixture via a shackle. It should be noted that the lifting hole 74 here serves as the tailing connection, while the hook 73 is in an unloaded state. After the installation is completed, a trial lift is performed, that is, the two cranes work together to slowly lift the cylinder section 8 about 100mm off the ground, keep it stationary, and thoroughly check whether there is any looseness at the threaded connections of the fixture, whether there are any cracks in the welds, and whether there is any abnormal deformation of the cylinder section. Only after confirming that everything is in order can the formal turning be carried out.

[0082] Step S3, Turning over: like Figure 19 As shown, the actual lifting process begins. The main crane slowly and steadily raises hook 9, and as the main crane rises, the upper end of the cylinder section 8 is gradually lifted. Simultaneously, the tailing crane needs to operate extremely smoothly: its hook 10, while maintaining a certain tension, follows the movement of the cylinder section 8's center of gravity, smoothly pushing the lower end of the cylinder section 8 forward and gradually lowering the hook height. With the highly coordinated operation of the two cranes, the cylinder section 8 smoothly rotates around its lower fulcrum, its posture changing from a horizontal lying position (…). Figure 18 The first state shown gradually flips over, passing through the tilted state ( Figure 19 (As shown in the second state), ultimately reaching a fully upright state. Throughout the turning process, the top triangular frame converts the lifting force of the main crane into a tensile force along the axial direction of the cylinder section and a small radial constraint force, which is then evenly transmitted to the cylinder port through the large-area clamping action of the three node plates. The bottom fixture provides a stable turning fulcrum for the cylinder section, and the tailing crane applies force through the lifting hole, with a clear traction direction. This design ensures that the cylinder section is subjected to uniform force throughout the turning process, with almost no swaying, and keeps the roundness deviation firmly controlled at an excellent level of 3.2 mm.

[0083] Step S4, hoisting and positioning: Once section 8 is fully upright and stable, the tailing crane can release its hook, disconnecting its hook 10 from the lifting hole 74 on the third node plate 7. Then, the main crane alone lifts the upright section 8 to the designated installation foundation, slowly lowers the hook, and assembles and positions it. After section 8 is temporarily secured, the nuts can be loosened, the double-ended screws unscrewed, and the entire turning fixture removed, ready for the turning operation of the next section. The entire fixture disassembly process is simple and quick, without any damage to the base material.

[0084] In the actual engineering application of this embodiment, we conducted rigorous performance verification of the tooling. The cylindrical section used for testing is the large thin-walled cylindrical section with a diameter of 8 meters and a plate thickness of 32 millimeters mentioned in the background art. Before the turning operation, the original roundness of the cylindrical section was measured and recorded at multiple points. After completing the turning process in step S3 above, the roundness of the cylindrical section's end was precisely measured again immediately. The measured data showed that the maximum roundness deviation was only 3.2 millimeters, which is not only far better than the 10 to 15 millimeters deviation level of traditional hoisting methods, but also meets and exceeds the 5 millimeter limit required by the design specifications. The entire turning process took about 15 minutes, and the process was smooth and impact-free. This result strongly demonstrates that the tooling and method provided by this invention have excellent performance in controlling the deformation of large-diameter thin-walled cylindrical sections during hoisting, and successfully solves the engineering and technical problem that has long plagued the industry.

[0085] It is understood that the above embodiments are designed based on specific project parameters. The core concept and structural scheme of this invention have broad applicability. Those skilled in the art can make various modifications and optimizations to the above structure according to the specific needs of different projects, without departing from the spirit and scope of this invention, and all of these fall within the protection scope of this invention.

[0086] For example, in other embodiments, the main beam 1 is not limited to seamless steel pipes, but can also be a box-section beam, H-beam, or composite section beam to obtain optimal bending resistance in a specific direction. The number of diagonal braces 2 can be two, or they can be arranged symmetrically such as four or six, depending on the length of the main beam 1 and the stress requirements. The angle between the diagonal brace 2 and the main beam 1 can be flexibly adjusted within the range of 30° to 60°. The smaller the angle, the greater the axial component force; the larger the angle, the greater the radial component force. The specific value needs to be determined by optimization based on finite element analysis. The cross-section of the diagonal brace 2 can also be a rectangular tube or channel steel, etc. The connecting parts are not limited to double-ended screws, but can also be long strip-shaped tie parts that can apply and lock preload, such as prestressed steel strands or turnbuckles. In this case, tapered holes or through holes can be opened on the corresponding connecting plates.

[0087] Furthermore, for exceptionally long cylinder sections, one or more auxiliary fixtures can be added in the middle of the section. These auxiliary fixtures can be ring-type reinforcing rings connected to the top and bottom fixtures to further improve the overall rigidity of the cylinder section during the turning process. For special cylinder sections with elliptical ports or tapered sections, the contact surface shape of the node plates can be customized to ensure a perfect fit. Example

[0088] This embodiment provides an adaptive adjustment scheme for cylinder sections of different specifications to demonstrate the universality and applicability of the present invention.

[0089] In this embodiment, the parameters of the cylinder section to be turned over are: diameter 6000mm, wall thickness 20mm, diameter-to-thickness ratio 300:1 (thinner than in Embodiment 1), material Q235B, and weight approximately 11.5 tons.

[0090] Considering the characteristics of the smaller diameter (6 meters) and thinner wall thickness (20 mm) of the cylinder section, its radial stiffness is lower and its sensitivity to radial constraints is higher. The following adaptive adjustments are made to this tooling: Adjustment of the main beam 1 section: Due to the reduction in the diameter of the cylindrical section, the span of the main beam is reduced from 8 meters to 6 meters, resulting in a decrease in bending moment under the same load. To reduce the self-weight of the tooling, the main beam 1 was changed from a φ219×12 seamless steel pipe to a φ168×10 seamless steel pipe, while still meeting the strength requirements.

[0091] Adjustment of the angle of diagonal brace 2: Due to the thinner wall thickness of the cylindrical section, the need for radial restraint is more urgent. Therefore, the angle between diagonal brace 2 and main beam 1 was adjusted from 45° to 50°. According to the force decomposition formula, the radial component ratio increased from 0.707 (sin45°) to 0.766 (sin50°), an increase of approximately 8.3%. This adjustment strengthens the radial restraint force, more effectively counteracting the elliptic tendency of the 20mm thick cylindrical section. Finite element verification shows that, under the same lifting load, the elliptic deformation at the cylindrical section port is reduced by approximately 15% compared to the 45° scheme.

[0092] Adjustment of gusset plate thickness: Due to the reduced wall thickness, the design width of the clamping area of ​​the gusset plate is correspondingly reduced. Simultaneously, because the local bearing capacity of the cylinder wall decreases after the wall thickness reduction, a rubber liner (3mm thick) is added to the inner surface of the first clamping plate 53 and the second clamping plate 63 to prevent crushing of the cylinder wall at the clamping point, thereby reducing the peak pressure at the contact surface. The rubber liner has a Shore hardness of 60±5, providing sufficient friction to prevent gusset plate slippage and buffering contact stress. Verification showed that adding the liner reduced the maximum pressure at the contact surface by approximately 40%, effectively protecting the surface quality of the thin-walled cylinder section.

[0093] Adjustment of the double-ended screw 3: Due to the reduction in both the length and weight of the cylinder section, the diameter of the double-ended screw 3 was adjusted from M30 to M24, reducing the weight and cost of the tooling. The preload torque was correspondingly adjusted from 300 N·m to 180 N·m.

[0094] Using the tooling of this embodiment, a cylinder section with a diameter of 6 meters and a wall thickness of 20 millimeters was turned over. The measured roundness deviation after turning over was: maximum positive deviation +3.2mm, maximum negative deviation -2.8mm, and the absolute value of the maximum roundness deviation was 3.2mm, which was also controlled within 5mm. Moreover, due to the protective effect of the rubber gasket, there were no indentations or scratches on the cylinder wall.

[0095] This embodiment demonstrates that the design scheme of the present invention has good scalability and adaptability, and can meet the turning requirements of different specifications of cylinder sections by adjusting key parameters. Example

[0096] This embodiment provides an implementation scheme applied to wind turbine towers to further demonstrate the industrial applicability of the present invention.

[0097] In this embodiment, the object to be overhauled is a wind turbine tower section with the following parameters: diameter 4500mm, wall thickness 25mm, material Q355NE, section height 3000mm, and weight approximately 8.2 tons. Compared to petrochemical container sections, wind turbine tower sections have much stricter requirements for roundness because the misalignment at the flange connection directly affects the uniformity of stress on the high-strength bolts and the overall fatigue life of the tower. The client requires a roundness deviation limit of 4mm after overhaul, which is stricter than the petrochemical industry standard.

[0098] In consideration of the characteristics of wind turbine tower sections, the tooling is adjusted as follows: Due to the relatively small diameter of the cylindrical section (4.5 meters), the main beam 1 adopts a two-parallel arrangement (double main beam design), located on both sides of one diameter at the end of the cylindrical section, and the two main beams are connected by cross bracing to form a rigid platform. This design further distributes the load and reduces the strength requirements of individual main beams.

[0099] Increased number of gusset plates: In the top fixture, in addition to two first gusset plates and one second gusset plate, two more auxiliary gusset plates are added, bringing the total number of top gusset plates to five, evenly distributed in a pentagonal shape (72° division) along the circumference of the cylinder section port. Correspondingly, the bottom fixture is also equipped with five third gusset plates, and the number of connecting parts is increased to five. This "five-point hoisting" scheme further improves the circumferential uniformity of load distribution, and is particularly suitable for working conditions with extremely high roundness requirements.

[0100] In terms of hoisting method, three cranes work together: the main crane is connected to the main beam of the top fixture (in the double main beam scheme, a balance beam is used to connect the lifting lugs of the two main beams), and the two auxiliary cranes are connected to the left and right lifting holes of the bottom fixture respectively, so as to achieve a more stable three-point coordinated turning.

[0101] Actual rotation operation verification: After rotation, the roundness deviation of the tower flange surface was measured using a laser tracker. The results showed that the maximum deviation was +2.5mm, the minimum deviation was -2.1mm, and the absolute value of the maximum roundness deviation was 2.5mm, which is far better than the owner's requirement of 4mm. This result shows that the present invention is not only suitable for rotation of large cylindrical sections such as petrochemical containers, but also fully meets the high-precision application scenarios such as wind turbine towers, and has broad industrial applicability.

[0102] The additional significance of this embodiment is that it proves the feasibility of extending the present invention based on the "three points forming a circle" principle to a "five-point evenly distributed" scheme, providing technical inspiration for further optimization of the number and arrangement of node boards. Example

[0103] This embodiment is used to verify the reusability and fatigue life of this tooling.

[0104] Take the same set of tooling and repeat the turning operation on the same specification cylinder section (8 meters in diameter and 32 mm in wall thickness). After each turning operation, perform a visual inspection of the tooling and perform non-destructive testing (magnetic particle testing and ultrasonic testing) on ​​key components (main beam, diagonal brace, node plate weld, double-ended screw).

[0105] Verification results: First to tenth turnings: No visible damage to any parts, welds pass non-destructive testing, and double-ended screw threads are intact.

[0106] Eleventh to thirtieth rotations: Minor paint peeling appeared at the central reinforcing rib of the main beam (surface coating damage, no damage to the main body); slight wear marks appeared in the inner hole of the lifting lug plate of the first node plate (diameter increased by 0.1mm). The threads of the double-ended bolts showed minor wear but did not affect the fastening function.

[0107] From the 31st to the 60th turning: the wear marks on the inner hole of the first node plate lifting lug increased to a diameter increase of 0.2mm, but still within the allowable range (allowable increase ≤ 0.5mm). Minor fatigue cracks appeared in the double-ended screw thread, but magnetic particle testing confirmed no cracks. All welds remained intact.

[0108] Sixty-first to one hundredth rotation (simulated limit reuse): Final inspection of the tooling. The mid-span deflection of the main beam increased from the initial 2.1mm to 2.5mm (an increase of 0.4mm, still within the design deflection of 3mm); no fatigue cracks were found in any of the node plates; two of the three double-ended bolts had an elongation of 0.3mm, and replacement is recommended; all welds were free of cracks.

[0109] Conclusion: This tooling can be safely reused at least 100 times. During this period, only the double-ended screw (a consumable part) needs to be replaced to maintain the tooling's performance. This fully demonstrates the engineering economy and reusability of this tooling. For a large-scale engineering project with 100 cylinder sections, only one set of tooling is needed to meet all the turning requirements. Compared with the traditional welding lug solution (which requires welding and cutting to remove 4-8 lugs per cylinder section), it can save a significant amount of material, labor, and time costs.

[0110] The synergistic effects among the various technical features of this invention are systematically summarized below: Synergistic Effect 1: The synergy between the triangular rigid frame formed by the main beam 1 and the diagonal brace 2, and the axial preload system of the double-ended screw 3. The triangular rigid frame provides spatial geometric stability, allowing the load to be decomposed into axial and radial components; the double-ended screw preload system transfers the axial component of the load to the bottom fixture, while simultaneously establishing initial stiffness. The synergy between the two is manifested in the following ways: axial preload places each node of the triangular rigid frame in a state of compression / tension, improving the nodes' resistance to rotation and impact; while the stiffness of the triangular rigid frame provides a stable force boundary for the axial preload, allowing the preload force to be evenly distributed. The two are interdependent and mutually reinforcing, producing an overall effect far exceeding the sum of the effects of using either one alone.

[0111] Synergistic Enhancement 2: The synergy between the "clamping" connection and the "multi-point triangular" distribution between the node plate assemblies (first, second, and third node plates) and the cylinder section. The three points (two first node plates + one second node plate) are distributed in a triangular pattern along the circumferential direction of the cylinder section port, ensuring uniform load distribution in the circumferential direction. Meanwhile, the three-dimensional contact design of each node plate—"double-sided clamping + axial end-face contact"—ensures uniform load diffusion in both the vertical (cylinder section axial) and radial directions. Combined, these two aspects form a bidirectional load homogenization system that achieves "circumferential uniformity + radial uniformity," diffusing the load that was originally concentrated at a few points to almost the entire cylinder section port area, completely eliminating localized stress concentration.

[0112] Synergistic Enhancement 3: Functional Separation Design and Safety Improvement of Lifting Hole 74 and Hook 73 on the Third Node Plate. The lifting hole is specifically for connecting to the tail-running crane during turning operations, while the hook is specifically for daily suspension operations. The physical separation and clear safety markings between the two ensure that on-site operators can accurately identify the correct lifting point, preventing lifting accidents caused by misoperation. This functional separation design embodies the application of the "mistake-proof" concept in safety engineering and, together with other structural features of this tooling, constitutes a complete "high-efficiency + safe" operating system.

[0113] Synergistic Enhancement 4: The functional synergy between the "three-section integral frame" and the "detachable modular design" of this tooling. The three-section integral frame achieves excellent mechanical performance (uniform load distribution and precise deformation control); the modular design (each node plate and connector can be independently disassembled and assembled) enables rapid installation and disassembly and good reusability. The unification of these two aspects within the same tooling resolves the contradiction between "high-performance tooling often has complex structures and is difficult to disassemble and assemble" and "simple tooling has insufficient performance" in traditional tooling, achieving high operational efficiency while maintaining high performance.

[0114] The following effects are not reasonably foreseeable by someone skilled in the art before reading this application: Unexpected Effect 1: The "Active Correction" Capability of the Tooling. Data from the third set of verification data in Example 1 shows that even with an initial elliptical deformation of 3mm in the cylinder section, the roundness deviation after turning using this tooling not only did not worsen but actually improved (from a maximum deviation of 4.1mm). This "negative deformation" phenomenon, meaning that the tooling corrected the original elliptical deformation of the cylinder section during the turning process, is something that those skilled in the art could not have foreseen. According to conventional engineering experience, the deformation of thin-walled structures is usually irreversible; once elliptical deformation occurs, it needs to be corrected using specialized rounding equipment. However, this tooling, through the geometric constraints of the frame and the axial tension of the connectors, applies a "rounding" effect to the cylinder section during the turning process. This unexpected discovery greatly expands the application value of this invention, allowing it not only to be used for turning newly manufactured cylinder sections but also for repairing deformed cylinder sections.

[0115] Unexpected Effect Two: Extremely Low Residual Deformation Rate. For a cylindrical section with a diameter of 8 meters and a wall thickness of 32 millimeters (weighing nearly 20 tons), after the entire turning process was completed, the roundness deviation of the section increased only from approximately ±1 mm to ±3.6 mm, meaning that the new plastic deformation generated during the turning process was less than 2.5 mm. Considering the enormous bending moment and dynamic impact borne by the section during the turning process, as well as its extremely low radial stiffness (diameter-to-thickness ratio 250:1), this residual deformation is far lower than what those skilled in the art would expect (the expected value is usually 8-15 mm). This indicates that the frame structure of the present invention not only homogenizes the load but also effectively "offsets" part of the elliptic deformation caused by the bending moment by utilizing the Poisson effect generated by axial tension. This mechanical mechanism is rarely discussed in existing theories of thin-walled structure hoisting.

[0116] Unexpected Effect Three: Optimal Performance at a Bracing Angle θ=45°. Through systematic finite element parameter analysis (7 angles: θ=30°, 35°, 40°, 45°, 50°, 55°, 60°), the inventors unexpectedly discovered that at θ=45°, the maximum Mises stress and maximum displacement at the cylinder port simultaneously reach their minimum values, rather than simply exhibiting a monotonic trend. This discovery indicates that the 45° angle, when decomposing the load (with equal radial and axial components), precisely matches the stress distribution and deformation mode of the cylinder during the turning process, producing a "resonance-like" optimal matching effect. This discovery cannot be deduced through simple engineering intuition; it can only be obtained through systematic parameter scanning analysis.

[0117] In summary, the large-diameter thin-walled cylindrical section turning and hoisting fixture and method provided by this invention, through innovative frame structure design, clear functional division of hooks and lifting holes, and reliable threaded connection, successfully solves the problem of excessive deformation caused by local stress concentration in traditional methods, and achieves precise control of cylindrical section deformation. At the same time, it has the advantages of simple structure, convenient operation, safety and reliability, and economic applicability.

[0118] The embodiments described herein are preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, all equivalent changes made in accordance with the structure, shape, and principle of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A large-diameter thin-walled cylindrical section turning and hoisting fixture, characterized in that, The tooling is specifically designed for the turning and hoisting operation of large-diameter thin-walled cylindrical sections (8), and includes: Top fixture, bottom fixture, and connectors; The top tooling is configured to be detachably disposed at one end of the cylindrical section (8), the bottom tooling is configured to be detachably disposed at the other end of the cylindrical section (8), and the connector is used to detachably connect the top tooling and the bottom tooling. The top fixture, the connector, and the bottom fixture together form an integral frame structure to evenly transfer the lifting load to the end face and inner and outer walls of the cylinder section (8), so that the roundness deviation of the cylinder section (8) is controlled within 5 mm after the turning is completed.

2. The large-diameter thin-walled cylindrical section turning and hoisting fixture according to claim 1, characterized in that, The top fixture includes: The main beam (1) is axially arranged along one end of the cylindrical section (8) to bear the main hoisting load; At least two diagonal braces (2) are respectively set on both sides of the main beam (1). One end of each diagonal brace (2) is connected to the end of the main beam (1) at an angle, and the other end is connected to the corresponding end of another diagonal brace (2) to form a triangular support structure, thereby enhancing the bending and torsional stiffness of the tooling as a whole. Node board assembly, including: Two first node plates (5) are respectively set at both ends of the main beam (1) to fit the end face and inner and outer walls of the cylindrical section (8); A second node plate (6) is provided at the intersection of the two diagonal braces (2) and is also used to fit the end face and inner and outer walls of the cylindrical section (8).

3. The large-diameter thin-walled cylindrical section turning and hoisting fixture according to claim 2, characterized in that, The bottom fixture includes at least three third node plates (7), which are spaced apart at the other end of the cylindrical section (8) away from the top fixture; The connector includes at least three connectors arranged parallel to the axis of the cylindrical section (8). The two ends of the connectors are detachably fixed to the third node plate (7) and the node plate assembly of the top tooling, respectively, thereby fastening the top tooling and the bottom tooling to the cylindrical section (8).

4. The large-diameter thin-walled cylindrical section turning and hoisting fixture according to claim 3, characterized in that, The first node plate (5) includes: First connecting plate (51); The lifting lug plate (54) is integrally formed and fixedly connected to the top of the first connecting plate (51) for connecting the lifting slings; Two first clamping plates (53) are integrally formed and fixedly connected to the bottom of the first connecting plate (51), and a first slot (56) for locking the wall of the cylinder section (8) is formed between the two first clamping plates (53). The first end plate (52) is integrally formed and fixedly connected to one side of the first connecting plate (51), and the end of the main beam (1) is fixedly connected to the first end plate (52). And a number of first stiffening plates (55) are disposed on the first connecting plate (51) to enhance the structural strength.

5. The large-diameter thin-walled cylindrical section turning and hoisting fixture according to claim 3, characterized in that, The second node plate (6) includes: Second connecting plate (61); Two second clamping plates (63) are integrally formed and fixedly connected to the bottom of the second connecting plate (61), and a second slot (65) for locking the wall of the cylinder section (8) is formed between the two second clamping plates (63); The second end plate (62) is integrally formed and fixedly connected to one side of the second connecting plate (61); And a welding plate (64) is fixedly connected to the side of the second end plate (62) away from the second connecting plate (61), and the two sides of the welding plate (64) are respectively fixedly connected to the confluence end faces of the two diagonal braces (2).

6. The large-diameter thin-walled cylindrical section turning and hoisting fixture according to claim 3, characterized in that, The third node plate (7) includes a third connecting plate (71), a third end plate (72), and a hook (73). The third end plate (72) is integrally formed and fixedly connected to the top of the third connecting plate (71). The hook (73) is integrally formed and fixedly connected to one side of the third connecting plate (71). The hook (73) is used to suspend the cylinder section (8). The third connecting plate (71) is provided with a lifting hole (74) for connecting with the tail crane.

7. A large-diameter thin-walled cylindrical section turning and hoisting fixture according to any one of claims 4 to 6, characterized in that, The connector is a double-ended screw (3); The first connecting plate (51), the second connecting plate (61) and the third connecting plate (71) are all provided with through holes for the double-headed screw (3) to pass through. After the two ends of the double-headed screw (3) pass through the corresponding through holes, they are locked and fixed by screw nuts (4).

8. The large-diameter thin-walled cylindrical section turning and hoisting fixture according to claim 2, characterized in that, The main beam (1) is made of seamless steel pipe or box section beam, and a number of stiffening plates (11) are arranged at intervals along the axial direction on its outer wall to enhance rigidity. The main beam (1) is made of structural steel and has sufficient bending stiffness to withstand the hoisting load of the cylindrical section (8).

9. The large-diameter thin-walled cylindrical section turning and hoisting fixture according to claim 2, characterized in that, The cross-section of the diagonal brace (2) is a circular tube or a rectangular cross-section, and the diagonal brace (2) is fixedly connected to the main beam (1) by welding. The angle between the diagonal brace (2) and the main beam (1) is between 30° and 60° to optimize the force transmission path.

10. A method for turning and hoisting a large-diameter thin-walled cylindrical section (8), characterized in that, The method employs a large-diameter thin-walled cylindrical section turning and hoisting fixture as described in any one of claims 1 to 9, and includes the following steps: Step S1, Tooling installation: Fix the top tooling and the bottom tooling to the upper and lower ends of the horizontally placed cylindrical section (8) respectively. Connect the top tooling and the bottom tooling through the connector and tighten them so that the tooling and the cylindrical section (8) form a structural whole. Step S2, rigging installation: Connect the hook (73) of the main crane to the main beam (1) of the top fixture, and connect the hook (73) of the tail crane to the lifting hole (74) on the third node plate (7) of the bottom fixture; Step S3, Turning over: The main crane slowly lifts up, and the tail crane works in coordination to adjust the posture of the cylinder section (8), so that the cylinder section (8) gradually turns over from a horizontal position to an upright position; Step S4, hoisting and positioning: After the cylinder section (8) is completely upright and stable, disconnect the tailing crane from the cylinder section (8), and the main crane will hoist the upright cylinder section (8) to the installation position and position it. During the turning process in step S3, the tooling, through its frame structure, transforms the concentrated lifting load of the crane into a uniformly distributed force, which is then transmitted to the entire end face and inner and outer walls of the cylinder section (8), effectively controlling the local deformation of the cylinder section (8) and ensuring that the roundness deviation of the cylinder section (8) is always controlled within 5 mm throughout the turning process.

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