Narrow cylinder assembly method and device

Abstract

The application discloses a narrow cylinder group assembling method and device, and the method comprises the following steps: hoisting adjacent cylinders to a group assembling roller, installing a clamp tool at one end, and the clamp angle is 110-130 degrees and perpendicular to the ring-shaped end face; hoisting the cylinders to the group assembling position after the cylinders are turned over and erected; driving the cylinders to rotate by an excess angle, then rotating back through a hand-operated hoist, detecting the change curve of the traction force during the traction process to determine the positioning state; after the bottom is welded, pre-tightening the steel wire ropes through the hand-operated hoist and the steel wire rope tool, the steel wire rope angle is 110-130 degrees and the fixed direction is perpendicular to the ring-shaped end face; after the hoisting chain is separated, the two steel wire rope tools are slowly tightened synchronously, and the ring-shaped positioning welding is performed.

Description

Technical Field

[0001] This invention relates to the field of wind turbine manufacturing technology, specifically to a method and apparatus for assembling narrow cylindrical bodies. Background Technology

[0002] In the wind turbine tower manufacturing industry, a narrow cylindrical structure refers to a cylindrical structure with a width of less than 1 meter and a diameter of no more than 5 meters, or a width of less than 1.5 meters and a diameter of more than 5 meters. The narrow cylindrical structure is an important component of wind turbine towers, and its assembly quality directly affects the overall structural strength, concentricity, and verticality of the tower.

[0003] The assembly of narrow cylindrical bodies relies primarily on traditional manual methods. Operators hoist adjacent cylindrical bodies onto a roller frame, visually inspect and manually adjust them to align their end faces, and then spot weld them for positioning. This method results in low assembly precision. Narrow cylindrical bodies have a large diameter and a narrow width, representing a typical "thin-walled, large-diameter" structure with poor rigidity. Circumferential positioning of the narrow cylindrical bodies on the rollers mainly relies on manually rotating the bodies and visually inspecting the corresponding weld seams for alignment. Positioning accuracy is highly dependent on the operator's skill level and lacks quantitative methods for judging the positioning status. Summary of the Invention

[0004] This invention provides a method and apparatus for assembling narrow cylindrical bodies, aiming to solve the technical problems of low positioning accuracy and low operation efficiency in existing narrow cylindrical body assembly.

[0005] To achieve the above objectives, the narrow cylindrical body assembly method provided by the present invention includes the following steps: S1. Hoist the first and second cylinders to be assembled onto the assembly rollers so that the adjacent end faces of the two cylinders are facing each other. S2. Install a clamping fixture at the end of the first cylinder away from the second cylinder. The clamping fixture includes two sets of clamping assemblies. The included angle between the two sets of clamping assemblies is 110° to 130°. The clamping direction of each clamping assembly is perpendicular to the circumferential end face of the first cylinder. S3. Use a hoisting chain to flip the first cylinder from a horizontal position to an upright position; S4. Hoist the first cylinder to the assembly position adjacent to the second cylinder, keeping the hook taut; S5. Drive the first cylinder to rotate around its own axis in the first direction to a first angle beyond the target position. Then, pull the first cylinder back to the target position in the second direction using a hand chain hoist. During the pulling process, detect the traction force change curve of the hand chain hoist. If the traction force change curve shows a jump or peak that exceeds the normal range, adjust the support position of the rollers on the first cylinder and repeat the above rotation and detection steps. S6. Perform root pass welding at the bottom of the joint between the first cylinder and the second cylinder; S7. The first cylinder is temporarily fixed by using a hand-operated hoist and wire rope tooling, so that the included angle between the two wire ropes is 110° to 130°, and the fixing direction of each wire rope is perpendicular to the circumferential end face of the first cylinder. The wire ropes are pre-tightened by using a hand-operated hoist. S8. After the hoisting chain is removed from the first cylinder, the two wire ropes are simultaneously and slowly tightened using a hand-operated hoist. S9. Start circumferential assembly and tack welding from the bottom of the butt joint. After the tack welding is completed, remove the clamping fixture. S10. After passing the inspection, complete the assembly.

[0006] Furthermore, the first direction is clockwise, the second direction is counterclockwise, and the first angle is 5° to 15°.

[0007] Furthermore, in step S5, the support position of the adjustment group on the roller is the height of the adjustment group on the roller.

[0008] Furthermore, in step S6, the welding length of the root pass is not less than 300mm.

[0009] Furthermore, tension sensors are installed on the wire ropes of the two chain hoists. Before pre-tensioning, the two wire ropes are tensioned synchronously, and the tension change curves of the two tension sensors over time are collected in real time.

[0010] Furthermore, using the tension change curve of the first wire rope as a benchmark, the tension change curve of the second wire rope is normalized over time. The tension difference between the two curves at each corresponding time point is calculated. The squares of each difference are summed and then divided by the number of sampling points to obtain the mean square error. When the mean square error is less than 5% of the average tension value of the benchmark curve, it is determined that the tension change trends of the two wire ropes are consistent. When the mean square error is greater than or equal to 5% of the average tension value of the benchmark curve, the tightening amount of the two hand-operated hoists is adjusted to make the tension change curves of the two wire ropes tend to be consistent until the mean square error is less than 5% of the average tension value of the benchmark curve.

[0011] Furthermore, in step S7, the two wire ropes are symmetrically arranged on both sides of the end face of the first cylinder, and the angle between the fixed point of the two sets of wire ropes at the edge of the end face of the first cylinder and the line connecting the center of the cylinder is 110° to 130°.

[0012] Furthermore, in step S9, the length of the tack weld is 30mm to 80mm, and the spacing between adjacent tack welds is 200mm to 400mm.

[0013] Furthermore, a protective layer is provided on the clamping surface of the clamping fixture.

[0014] The present invention also provides a narrow cylindrical body assembly device, including assembly rollers, clamping fixtures, lifting chains, and wire rope fixtures. The clamping fixture includes at least two sets of clamping assemblies, with an included angle of 110° to 130° between each clamping assembly, and the clamping direction of each clamping assembly is perpendicular to the circumferential end face of the narrow cylindrical body. The wire rope fixture includes at least two sets of wire ropes and a hand-operated hoist; one end of each set of wire ropes is fixed to the end edge of the narrow cylindrical body by clamps, and the other end of each set of wire ropes converges at the hook of the hand-operated hoist.

[0015] This invention limits the included angle between the two clamps of the clamping fixture to 110° to 130° and ensures that the clamping direction is perpendicular to the circumferential end face. This results in a symmetrical distribution of clamping force on the cylinder end face, with the resultant force passing through the center of the cylinder. This avoids additional bending moments and deformations at the cylinder end due to uneven force distribution, thus improving radial positioning accuracy. Furthermore, this invention establishes a quantitative method for determining the positioning status by first driving the cylinder to rotate forward by an excessive angle during the positioning process, and then using a hand-operated hoist to pull it back in the opposite direction. The fluctuation amplitude of the traction force change curve during the rotation process is used to determine the positioning status, solving the problem of traditional positioning relying on operator experience. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the device shown in this invention.

[0017] Figure 2 This is a structural schematic diagram of the device at point A shown in the present invention. Detailed Implementation

[0018] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It is to be understood that the specific embodiments described herein are merely illustrative of this application and not intended to limit it. All other embodiments obtained by those skilled in the art based on the embodiments in this application without inventive effort are within the scope of protection of this application.

[0019] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0020] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly or implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0021] Figure 1 and Figure 2 A schematic diagram of the narrow cylindrical body assembly device according to an embodiment of the present invention is shown. Figure 1 and Figure 2 As shown, the present invention provides a method and apparatus for assembling narrow cylindrical bodies, which is mainly used in the wind tower manufacturing industry for assembling narrow cylindrical bodies with a width of less than 1 meter and a diameter of no more than 5 meters, or a width of less than 1.5 meters and a diameter of more than 5 meters.

[0022] The narrow cylindrical assembly device of the present invention mainly includes assembly rollers, clamping fixtures, hoisting chains, and wire rope fixtures.

[0023] The assembly rollers are located at the assembly station to support narrow cylinders. There are two sets of assembly rollers, corresponding to the first and second cylinders respectively. Each set includes two support rollers, positioned on either side of the cylinder's radial direction, supporting the cylinder from below and allowing it to rotate freely around its own axis on the rollers. The rollers make rolling contact with the outer wall of the cylinder, resulting in low friction and facilitating cylinder rotation by operators or drive units. The assembly rollers can accommodate cylinders of different diameters.

[0024] The clamping fixture is mounted on the end edge of the narrow cylinder. The clamping fixture includes at least two sets of clamping assemblies, with an included angle of 110° to 130° between each assembly. The clamping direction of each assembly is perpendicular to the circumferential end face of the narrow cylinder. A protective layer, made of rubber or polyurethane, is provided on the clamping surface of the clamping fixture to prevent indentations or scratches on the surface of the narrow cylinder during clamping. The clamping assemblies are fixed to the end edge of the cylinder, and each set of clamping assemblies is installed independently.

[0025] Lifting chains are used for lifting and turning narrow cylinders. One end of the lifting chain is attached to the end of the narrow cylinder furthest from the second cylinder, and the other end is attached to the crane hook. The length and load-bearing capacity of the lifting chain are selected based on the weight and size of the narrow cylinder.

[0026] The wire rope fixture includes at least two sets of wire ropes and a hand-operated hoist. One end of each set of wire ropes is secured to the end edge of the narrow cylinder by clamps, and the other ends of each set of wire ropes converge at the hook of the hand-operated hoist. The hand-operated hoist is used to tighten or release the wire ropes to apply or release axial preload to the narrow cylinder. Two hand-operated hoists are used, one for each set of wire ropes, and each hoist can be operated independently.

[0027] The following provides a detailed description of the assembly method for the narrow cylindrical body assembly of the present invention. The method includes the following steps: S1. Hoist the first and second cylinders to be assembled onto the assembly rollers, ensuring their adjacent end faces are facing each other. Specifically, the first and second cylinders are placed between the two support rollers of their respective assembly rollers. The initial distance between the adjacent end faces of the two cylinders is controlled between 50mm and 100mm to facilitate subsequent adjustments and welding operations. The axes of the two cylinders are initially aligned, making their adjacent end faces approximately parallel.

[0028] S2. Install a clamping fixture at the end of the first cylinder furthest from the second cylinder (i.e., the outer end of the first cylinder). The clamping fixture includes two sets of clamping assemblies, with an included angle of 110° to 130°, preferably 120°, between the two sets of clamping assemblies. The clamping direction of each clamping assembly is perpendicular to the circumferential end face of the first cylinder. The clamping fixture is installed as follows: fix the two sets of clamping assemblies into the flange holes or process holes at the edge of the end face of the first cylinder, adjust the position of the two clamping assemblies so that the included angle between them is approximately 120°, and the clamping surfaces of the clamps are tightly fitted against the outer wall surface or end face edge of the cylinder. A protective layer, made of rubber or polyurethane, is provided on the clamping surface of the clamping fixture to prevent damage to the cylinder surface during clamping. After the clamping fixture is installed, the two sets of clamping assemblies form symmetrical fixing points on the end face of the cylinder, the clamping force is evenly distributed on the end face, and the resultant force passes through the center of the cylinder.

[0029] S3. Use a hoisting chain to flip the first cylinder from a horizontal position to an vertical position. Specifically, connect one end of the hoisting chain to the end of the first cylinder furthest from the second cylinder, and the other end to the crane hook. The crane slowly lifts the cylinder, gradually flipping it around its bottom edge. During the flipping process, the rollers provide support and guidance, allowing the cylinder to smoothly transition from a horizontal to an vertical position.

[0030] S4. Lift the first cylinder to the assembly position adjacent to the second cylinder, keeping the hook taut. At this time, the lifting chain still bears all or most of the weight of the first cylinder, and the hook remains firm, ensuring the first cylinder is in a stable vertical position for subsequent circumferential positioning operations. The hook tension is maintained by crane operation; the operator communicates with the crane driver via walkie-talkie to ensure the hook remains taut at all times.

[0031] S5. Drive the first cylinder to rotate around its own axis in the first direction to a first angle exceeding the target position. Then, use a hand-operated hoist to pull the first cylinder back to the target position in the second direction. During the pulling process, detect the change curve of the pulling force of the hand-operated hoist. If the fluctuation amplitude of the pulling force change curve is less than a first threshold, the positioning is confirmed to be complete. If the fluctuation amplitude is greater than the first threshold, adjust the support position of the assembly rollers on the first cylinder and repeat the above rotation and detection steps. The first direction is clockwise, the second direction is counterclockwise, and the first angle is 5° to 15°.

[0032] In the above steps, the narrow cylinder rolls on the assembly rollers, and there is rolling contact between the outer wall of the cylinder and the rollers. Due to manufacturing errors of the cylinder and roller installation errors, there is a certain random deviation between the rotational position of the cylinder on the rollers and the theoretical position, including positioning errors caused by factors such as roller clearance and cylinder roundness deviation. If the cylinder is directly driven to rotate to the target position, these errors cannot be eliminated. In this step, the cylinder is first driven to rotate clockwise to a first angle of 5° to 15° beyond the target position, so that the cylinder passes the target position. Then, the cylinder is manually rotated and slowly rotated back to the target position. During the rotation, the cylinder moves in the opposite direction to the previous driving direction.

[0033] The traction force variation curve of the hand-operated hoist was monitored during the traction process. The operator slowly pulled the first cylinder to rotate in the second direction using the hand-operated hoist. During rotation, the first cylinder rolled on the paired rollers, and the position of its center of gravity relative to the roller support point changed continuously. The traction force of the hand-operated hoist was used to overcome the rolling resistance torque of the cylinder and the additional resistance torque caused by the change in the position of the cylinder's center of gravity. Under ideal conditions, with the cylinder's appearance intact, the rollers at consistent height, and no foreign objects between the cylinder and the rollers, the traction force changed smoothly with the rotation angle of the cylinder. In the initial stage of rotation, the center of gravity of the cylinder gradually rose relative to the support point, and the traction force gradually increased; after the cylinder's center of gravity passed directly above the support point, the center of gravity gradually decreased, and the traction force gradually decreased. During this process, the traction force curve was a smooth, continuous single-peak curve.

[0034] Meanwhile, the operator continuously monitors the traction force changes of the chain hoist during traction. If there is a roundness deviation in the cylinder, with local bulges or depressions on the circumference of the cylinder, this local defect will cause a momentary change in the roller support height when passing through the rollers, resulting in a sudden change in the cylinder's center of gravity position. The traction force curve will then show a momentary jump outside the normal range at this location. If the roller support height is uneven, the cylinder will periodically exhibit a phenomenon where one side is higher than the other during rotation, and the traction force curve will show periodic abnormal jumps related to the roller position. If there are foreign objects or welding slag on the cylinder surface, these objects will generate additional resistance when passing through the rollers, causing a momentary spike in the traction force curve.

[0035] When the amplitude of the traction force variation curve remains within the normal range, it indicates that the cylinder has not encountered abnormal resistance during the entire rotation process, and the cylinder is in a normal rotation state, indicating that positioning is complete. When the traction force variation curve shows jumps or peaks outside the normal range, it indicates that there is abnormal resistance in the cylinder during rotation. In this case, it is necessary to adjust the support position of the assembly rollers on the first cylinder, that is, adjust the height of the assembly rollers.

[0036] When the narrow cylinder is upright on the assembly rollers, its lower end is supported by the clamping fixture and the assembly rollers, while its upper end is held by the lifting chain. In this state, the position of the first cylinder's axis in the vertical plane is affected by the suspension position of the hook, the fixed position of the clamping fixture at the end of the cylinder, and the support height of the assembly rollers. When the heights of the two sets of assembly rollers are inconsistent, the first cylinder will tilt vertically, and its axis will deviate from the theoretical plumb line in the vertical plane, resulting in a misalignment at the mating end faces of the first and second cylinders in the vertical direction. This misalignment will be reflected in the traction force change curve during the rotation process.

[0037] It should be noted that "consistent curve trends" means that the tension changes of the two wire ropes have the same waveform characteristics during the tensioning process. In the initial stage of tensioning, the tension of both wire ropes starts from zero and increases at similar rates. When the operating rhythm of the hand-operated hoist changes, the tension of both wire ropes fluctuates simultaneously with the operating rhythm. When tension reaches a stable state, the tension of both wire ropes approaches their respective final values ​​simultaneously. If the tension change curves of the two wire ropes are basically identical in shape, but there is a fixed deviation in value, it indicates that the first cylinder is offset in the horizontal direction, resulting in a greater force on one side of the wire rope and a smaller force on the other. If the tension change curves of the two wire ropes are inconsistent in shape, it indicates that the first cylinder is jammed or tilted during rotation.

[0038] S6. Perform a root pass weld at the bottom of the joint between the first and second cylinders. The weld length of the root pass weld shall not be less than 300mm. The purpose of the root pass weld is to fix the two cylinders together at the bottom, providing a safety guarantee for the subsequent removal of the hoisting chain and the simultaneous slow tightening of the two wire ropes. The requirement of a weld length of not less than 300mm is based on strength calculations—this weld length is sufficient to withstand the self-weight of the first cylinder and the additional load generated by subsequent operations, preventing displacement or overturning of the cylinders at the moment of removal of the hoisting chain.

[0039] S7. The first cylinder is temporarily fixed using a hand-operated hoist and wire rope fixture, ensuring the angle between the two wire ropes is 110° to 130°. The fixing direction of each wire rope is perpendicular to the circumferential end face of the first cylinder. The wire ropes are pre-tightened using the hand-operated hoist. The wire rope fixture includes at least two sets of wire ropes. One end of each wire rope is fixed to the end edge of the first cylinder by clamps, and the other end converges to the hook of the hand-operated hoist. The two wire ropes are symmetrically arranged on both sides of the end face of the first cylinder. The angle between the fixing points of the two sets of wire ropes at the edge of the end face of the first cylinder and the line connecting them to the center of the cylinder is 110° to 130°, preferably 120°. The fixing direction of the two wire ropes is perpendicular to the circumferential end face of the first cylinder, ensuring that the pre-tightening force of the wire ropes is applied axially rather than tangentially along the cylinder.

[0040] Before pre-tensioning the wire ropes, a quantitative detection of the alignment status is performed. Tension sensors are installed on the wire ropes of the two hand-operated hoists. Before pre-tensioning, both wire ropes are tensioned synchronously, and the tension change curves of the two tension sensors over time are collected in real time. Using the tension change curve of the first wire rope as a benchmark, the tension change curve of the second wire rope is normalized over time. The tension difference between the two curves at corresponding time points is calculated, and the sum of the squared differences is divided by the number of sampling points to obtain the mean square error (MSE). When the MSE is less than 5% of the average tension value of the benchmark curve, the tension change trends of the two wire ropes are considered to be consistent, indicating that the first cylinder is horizontally aligned and the two wire ropes are evenly stressed. When the MSE is greater than or equal to 5% of the average tension value of the benchmark curve, the tension change trends of the two wire ropes are considered to be inconsistent, indicating that the first cylinder is horizontally offset and the two wire ropes are unevenly stressed. At this point, adjust the tightening amount of the two hand chain hoists to make the tension change curves of the two wire ropes more consistent, until the mean square difference is less than 5% of the average tension value of the reference curve.

[0041] After pre-tensioning, the wire rope is in a preliminary tensioned state, providing auxiliary support for the first cylinder. At this time, the wire rope fixture only bears part of the load and does not affect the subsequent removal operation of the hoisting chain.

[0042] S8. After detaching the hoisting chain from the first cylinder, simultaneously and slowly tighten the two wire rope fixtures using a hand-operated hoist. During this period, the wire rope fixtures are only in a pre-tightened state. After the bottom weld is completed, detach the hoisting chain and immediately and simultaneously and slowly tighten the two wire rope fixtures. At this point, the axial position of the first cylinder is double-fixed by the bottom weld and the wire rope fixtures. The operator disconnects the hoisting chain from the cylinder, removes the hoisting chain from the cylinder, and allows the wire ropes to reach the tensioned state of the simultaneously and slowly tightened two wire rope fixtures, applying an axial preload to the first cylinder. The time interval between detaching the hoisting chain and simultaneously and slowly tightening the two wire rope fixtures should be as short as possible to ensure that the first cylinder remains stable throughout the entire switching process.

[0043] S9. Begin circumferential assembly tack welding from the bottom of the butt joint. The length of each tack weld should be 30mm to 80mm, and the spacing between adjacent tack welds should be 200mm to 400mm. Tack weld symmetrically from the bottom to both sides circumferentially to control welding deformation. Remove the clamping fixture after the tack welding is completed.

[0044] After passing self-inspection and special inspection, S10 is assembled and then proceeds to the assembly process of the next tower section.

[0045] The technical effects of the present invention will be described in detail below through specific embodiments and comparative examples.

[0046] Example 1 In a wind turbine manufacturing project, a narrow cylindrical body with a diameter of 4.5m and a width of 0.8m was assembled. The assembly method and apparatus of this invention were used. The clamping fixture has two clamps with an angle of 120°, with a first angle of 10°. The wire rope fixture has two wire ropes with an included angle of 120°. The bottom root weld length is 350mm, the tack weld length is 50mm, and the tack weld spacing is 300mm. The tension sensor has a sampling frequency of 100Hz.

[0047] After assembly, the concentricity deviation at the joint of the two cylinders was measured to be 1.2 mm, and the misalignment was 0.8 mm, meeting the design requirements of a concentricity deviation of no more than 2 mm and a misalignment of no more than 1 mm. The total assembly time for a single cylinder section was 2.5 hours.

[0048] Example 2 Under the same working conditions, a comparative test was conducted by changing only the included angle between the two clamping components of the clamping fixture. When the included angle between the two clamps was 90°, the clamping force distribution on the end face of the cylinder was asymmetrical, and the resultant force did not pass through the center of the cylinder. After assembly, the concentricity deviation was 3.5mm, exceeding the design requirements. When the included angle between the two clamps was 150°, the clamping force distribution was also asymmetrical, and the concentricity deviation after assembly was 3.0mm. When the included angle between the two clamps was 120°, the clamping force formed a symmetrical force system with an equilateral triangular distribution on the end face, and the resultant force passed through the center of the cylinder, with a concentricity deviation of 1.2mm.

[0049] Example 3 Under the same working conditions, a comparative test was conducted by changing only the included angle between the two wire ropes of the wire rope fixture. When the included angle between the two wire ropes was 90°, the component of the wire rope preload along the axial direction of the cylinder decreased, the preload effect was reduced, and the concentricity deviation after assembly was 2.8 mm. When the included angle between the two wire ropes was 150°, the distribution of the fixing points of the wire ropes on the end face of the cylinder was too dispersed, the preload was uneven, and the concentricity deviation after assembly was 3.2 mm. When the included angle between the two wire ropes was 120°, the axial component of the preload was the largest, and the horizontal components canceled each other out, and the concentricity deviation was 1.2 mm.

[0050] Example 4 Under the same working conditions, the standard deviation (SD) method of the tension curve of this invention was used for alignment detection and adjustment. The tension change curves of the two wire ropes were collected, and the SD value was calculated. Initially, the SD value was 12% of the average tension value of the reference curve, which was greater than the 5% threshold. The operator adjusted the tension of the two hand-operated hoists respectively. After three adjustments, the SD value decreased to 3.8%, which was less than the 5% threshold. At this point, it was determined that the tension change trends of the two wire ropes were consistent, and the first cylinder was in an aligned state. After assembly, the concentricity deviation was measured to be 1.0 mm, which is better than Example 1, which did not use tension detection and adjustment.

[0051] Comparative Example 1 Narrow cylindrical sections of the same specifications were assembled using traditional assembly methods. This method employed a crane for manual adjustment, without the use of clamps or wire ropes. Temporary fixation was achieved by welding temporary blocks to the ends of the cylindrical sections. After assembly, the concentricity deviation was measured to be 6.5 mm, and the misalignment was 3.2 mm. The total assembly time for a single cylindrical section was 5.5 hours.

[0052] Comparative Example 2 The device of this invention was used, but the rotation and re-rotation positioning operation was not performed; the remaining steps were the same as in Example 1. After assembly, the concentricity deviation was measured to be 3.8 mm.

[0053] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the invention patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the protection scope of the present invention. Therefore, the protection scope of this invention patent should be determined by the appended claims.

Claims

1. A method for assembling narrow cylindrical bodies, characterized in that, Includes the following steps: S1. Hoist the first and second cylinders to be assembled onto the assembly rollers so that the adjacent end faces of the two cylinders are facing each other. S2. Install a clamping fixture at the end of the first cylinder away from the second cylinder. The clamping fixture includes two sets of clamping assemblies. The included angle between the two sets of clamping assemblies is 110° to 130°. The clamping direction of each clamping assembly is perpendicular to the circumferential end face of the first cylinder. S3. Use a hoisting chain to flip the first cylinder from a horizontal position to an upright position; S4. Hoist the first cylinder to the assembly position adjacent to the second cylinder, keeping the hook taut; S5. Drive the first cylinder to rotate around its own axis in the first direction to a first angle beyond the target position. Then, use a hand chain hoist to pull the first cylinder back to the target position in the second direction. During the pulling process, detect the traction force change curve of the hand chain hoist. If the amplitude of the traction force change curve is within the normal range, the positioning is confirmed to be complete. If the traction force change curve shows a jump or peak that exceeds the normal range, adjust the support position of the set rollers on the first cylinder and repeat the above rotation and detection steps. S6. Perform root pass welding at the bottom of the joint between the first cylinder and the second cylinder; S7. The first cylinder is temporarily fixed by using a hand-operated hoist and wire rope tooling, so that the included angle between the two wire ropes is 110° to 130°, and the fixing direction of each wire rope is perpendicular to the circumferential end face of the first cylinder. The wire ropes are pre-tightened by using a hand-operated hoist. S8. After the hoisting chain is removed from the first cylinder, the two wire ropes are simultaneously and slowly tightened using a hand-operated hoist. S9. Start circumferential assembly and tack welding from the bottom of the butt joint. After the tack welding is completed, remove the clamping fixture. S10. After passing the inspection, complete the assembly.

2. The method according to claim 1, characterized in that, The first direction is clockwise, the second direction is counterclockwise, and the first angle is 5° to 15°.

3. The method according to claim 1, characterized in that, In step S5, the support position of the adjustment group on the roller is the height of the adjustment group on the roller.

4. The method according to claim 1, characterized in that, In step S6, the welding length of the root pass is not less than 300mm.

5. The method according to claim 1, characterized in that, Tension sensors are installed on the wire ropes of the two hand chain hoists. Before pre-tensioning, the two wire ropes are tensioned synchronously, and the tension change curves of the two tension sensors over time are collected in real time.

6. The method according to claim 5, characterized in that, Using the tension change curve of the first wire rope as a benchmark, the tension change curve of the second wire rope is normalized over time. The tension difference between the two curves at each corresponding time point is calculated. The squares of each difference are summed and then divided by the number of sampling points to obtain the mean square error. When the mean square error is less than 5% of the average tension value of the benchmark curve, the tension change trends of the two wire ropes are determined to be consistent. When the mean square error is greater than or equal to 5% of the average tension value of the reference curve, adjust the tightening amount of the two hand chain hoists to make the tension change curves of the two wire ropes tend to be consistent, until the mean square error is less than 5% of the average tension value of the reference curve.

7. The method according to claim 1, characterized in that, In step S7, two steel wire ropes are symmetrically arranged on both sides of the end face of the first cylinder, and the angle between the fixed point of the two sets of steel wire ropes at the edge of the end face of the first cylinder and the line connecting the center of the cylinder is 110° to 130°.

8. The method according to claim 1, characterized in that, In step S9, the length of the tack weld is 30mm to 80mm, and the spacing between adjacent tack welds is 200mm to 400mm.

9. The method according to claim 1, characterized in that, The clamping surface of the clamping fixture is provided with a protective layer.

10. A narrow cylindrical body assembly device, characterized in that, include: Assembly rollers; The clamping fixture includes at least two sets of clamping assemblies, with an included angle of 110° to 130° between each clamping assembly, and the clamping direction of each clamping assembly is perpendicular to the circumferential end face of the narrow cylinder. hoisting chain; A wire rope fixture, comprising at least two sets of wire ropes and a hand-operated hoist, wherein one end of each set of wire ropes is fixed to the end edge of a narrow cylinder by clamps, and the other end of each set of wire ropes converges to the hook of the hand-operated hoist.

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