A wide-diameter roundness-finding machine and method for assisting field butt welding

Abstract

This invention discloses an auxiliary on-site assembly welding machine and method for finding the diameter of pipes and cylindrical containers, relating to the field of on-site welding fixtures for pressure vessels and pressure pipelines. The device employs a prefabricated gantry frame, equipped with a double-sided drive mechanism and positive and negative threaded shafts. The finding mechanism uses multiple sets of fan-shaped connecting rod assemblies, which, through the cooperation of circumferential limiting components and axial limiting devices, can switch between radial diameter finding and circumferential rolling rounding operation modes. The method completes the operation in five steps: station setup, fixed-point top pressure for rough rounding, axial locking for switching operation modes, circumferential rolling for fine rounding, and demolding and unloading. The entire process utilizes cold deformation processing technology. The modular design of this invention facilitates rapid on-site deployment. The dual-mode operation balances processing efficiency and roundness accuracy. Cold processing eliminates the need for subsequent heat treatment, significantly improving the efficiency and quality of rounding construction before welding pipelines and cylindrical containers. It is suitable for batch on-site operations such as long-distance pipelines and pumped storage pressure pipelines.

Description

Technical Field

[0001] This invention relates to the field of auxiliary tooling technology for on-site welding of pressure vessels and pressure pipelines, and in particular to a wide-diameter roundness finding machine and method for assisting on-site assembly welding. Background Technology

[0002] In large-scale engineering construction, there are numerous on-site welding operations for metal components, which cannot rely entirely on factory prefabrication followed by on-site assembly. Examples include the on-site assembly of long-distance natural gas pipelines, pumped storage power station pressure pipelines, and large thermal power and chemical pressure vessels and pipelines. The primary steps in on-site welding operations are pipe end alignment and rounding.

[0003] Due to the batch procurement of pipe materials and the parallel construction of multiple sections, the processing of the main components is inconsistent. In addition, factors such as the manufacturer's processing accuracy deviation, residual stress in the material, temperature and humidity changes, and deformation during transportation often cause problems such as excessive ovality and diameter deviation at the pipe ends of cylindrical workpieces. Furthermore, the lack of large-scale machining equipment at the construction site and the inefficiency of traditional rounding procedures severely restrict the progress of welding construction, and improper handling can easily lead to equipment safety hazards.

[0004] In the prior art, for example, the patent with publication number CN120095501A proposed a butt welding device for large-diameter steel pipes, which only has welding and limiting functions and does not solve the technical problem of finding the roundness of the pipe end; the patent with publication number CN104475599A proposed a method and device for widening the diameter of spiral steel pipe ends, which can only widen the diameter of pipe ends with smaller diameters within the tolerance range of the pipe ends. It has a single function and is difficult to adapt to complex on-site working conditions and batch processing needs. Summary of the Invention

[0005] To address the aforementioned deficiencies in existing technologies, the present invention aims to provide an auxiliary on-site assembly welding wide-diameter roundness finding machine and method. It employs a modular assembly structure, facilitating on-site transportation and rapid assembly. Through an umbrella-rib type fan-rib connecting rod structure and a limit switching mechanism, it achieves dual-mode operation of radial expansion and contraction of the wide diameter and circumferential rotation of the roller. The use of cold deformation processing technology avoids residual stress and subsequent heat treatment processes, significantly improving the efficiency and accuracy of on-site pipe end roundness finding.

[0006] To achieve the above objectives, the present invention provides, in one aspect, an auxiliary on-site assembly welding wide-diameter roundness finding machine, comprising a gantry frame, with drive mechanisms installed in pairs on both sides of the gantry frame, the output shaft of the drive mechanism being connected to a threaded shaft via a coupling; a suspension mechanism for suspending cylindrical workpieces is installed on the top of the gantry frame; a fixing mechanism for radially positioning and supporting the rotation of the cylindrical workpiece is fixed on the top of the gantry frame; a roundness finding mechanism is mounted on the threaded shaft; the roundness finding mechanism includes multiple sets of fan-shaped connecting rod assemblies, circumferential limiting assemblies, and axial limiting devices; each set of fan-shaped connecting rod assemblies includes a roundness finding roller, a support rod, and a positioning terminal; the positioning terminal is threadedly engaged with the threaded shaft, and an axial limiting device is installed between the positioning terminal and the threaded shaft; the two ends of the support rod are respectively hinged to the positioning terminal and the roundness finding roller; the multiple sets of fan-shaped connecting rod assemblies are distributed circumferentially along the threaded shaft, forming a radially openable umbrella-shaped structure; The circumferential limiting component selectively restricts the circumferential rotation of the umbrella-shaped structure relative to the cylindrical workpiece. When the circumferential limiting component restricts the circumferential rotation, the drive mechanism drives the threaded shaft to rotate, drives the positioning terminal to move axially, and causes the fan-shaped connecting rod assembly to open radially, thereby achieving wide-diameter rounding. When the circumferential limiting component releases the circumferential rotation restriction, the axial limiter locks the axial movement between the positioning terminal and the threaded shaft. The drive mechanism will drive the threaded shaft and the rounding mechanism to rotate as a whole, and the rounding roller will roll along the inner wall of the cylindrical workpiece to achieve roller rounding and complete rounding.

[0007] Preferably, the gantry frame includes a crossbeam, two columns, and a base; the lower end of the column is detachably connected to the base, and the upper end is detachably connected to the crossbeam; a diagonal brace is provided between the column and the crossbeam.

[0008] Preferably, the drive mechanism includes a motor and a gearbox; the output end of the motor is connected to the input end of the gearbox, and the output end of the gearbox is coaxially connected to a threaded shaft via a coupling.

[0009] Preferably, the suspension mechanism includes a hoist and a hanging cable; the hoist is slidably mounted on the crossbeam of the gantry frame, and the hanging cable is connected to the lower end of the hoist for lifting cylindrical workpieces.

[0010] Preferably, the fixing mechanism includes an adjustable length support rod, a fixed shaft, and a roller; the adjustable length support rod is installed on the gantry frame, the fixed shaft is located at the end of the adjustable length support rod, and the roller is rotatably fitted onto the fixed shaft to abut against and support the outer wall of the cylindrical workpiece.

[0011] Preferably, the round-finding mechanism includes at least two pairs of sector-type connecting rod assemblies, each pair including a first sector-type connecting rod assembly and a second sector-type connecting rod assembly; the first positioning terminal of the first sector-type connecting rod assembly and the second positioning terminal of the second sector-type connecting rod assembly have opposite internal thread directions, respectively cooperating with the forward-rotating thread section and the reverse-rotating thread section of the threaded shaft.

[0012] Preferably, both ends of the threaded shaft are symmetrically provided with a forward-rotating thread section and a reverse-rotating thread section, so that the fan-shaped connecting rod assemblies arranged symmetrically on both sides can open or close synchronously during the rotation of the threaded shaft.

[0013] Preferably, the circumferential limiting component is clamped at the opening of the cylindrical workpiece using on-site pliers or clamps, thereby restricting the overall circumferential rotation of the rounding mechanism relative to the cylindrical workpiece.

[0014] Preferably, the axial limiter is a threaded sleeve fitted on the threaded shaft. After the fan-shaped connecting rod assembly is opened to the position, the threaded sleeve locks the corresponding first positioning terminal and second positioning terminal, thereby making the threaded shaft and the rounding mechanism form an integral whole.

[0015] Preferably, the rounding roller includes a roller bracket, a roller support rod, a roller body, a hinge support, and a hinge shaft; the roller support rod is mounted on the roller bracket, and the roller body is rotatably mounted on the roller bracket; the roller bracket is mounted on the hinge support, and the hinge support is hinged to the support rod via the hinge shaft.

[0016] A second aspect of the present invention provides a method for finding the wide diameter circle for assisting on-site assembly welding, comprising the following steps: S1, Workstation setup and workpiece positioning: Assemble the gantry frame, install the drive mechanism in pairs on both sides of the gantry frame, and connect the threaded shaft through the coupling; suspend the cylindrical workpiece to the workstation through the suspension mechanism, adjust the fixing mechanism to radially position the cylindrical workpiece and determine its rotation axis; fit the rounding mechanism onto the threaded shaft at the position corresponding to the opening of the cylindrical workpiece. S2, Radial Expansion Diameter Rough Rounding: Activate the circumferential limiting component to restrict the circumferential rotation of the umbrella-shaped structure relative to the cylindrical workpiece; start the drive mechanism to drive the threaded shaft to rotate, drive the positioning terminal to move axially along the threaded shaft, causing each set of fan-shaped connecting rod assemblies to open radially, and the rounding rollers press against the inner wall of the cylindrical workpiece to achieve cold expansion; after holding the pressure for a set time, reverse the drive of the threaded shaft to make the fan-shaped connecting rod assemblies radially retract; adjust the circumferential angle of the cylindrical workpiece, and repeat the above opening, holding, and retracting actions to complete the rough rounding; S3, Axial Locking and Operating Condition Switching: After the fan-shaped connecting rod assembly opens to the target diameter for the last time, install the axial limiter to lock the axial relative movement between the positioning terminal and the threaded shaft; release the circumferential limit assembly from restricting the circumferential rotation of the umbrella-shaped structure. S4, Circumferential Roller Finishing Round: The start-up drive mechanism drives the threaded shaft and the rounding mechanism to rotate coaxially. The rounding rollers continuously roll and press along the inner wall of the cylindrical workpiece to uniformly shape the entire circumference of the tube opening and complete the finishing round. S5, Demolding and Workpiece Removal: After stopping the machine, reactivate the circumferential limiting component, remove the axial limiting device, reverse drive the threaded shaft to make the fan-shaped connecting rod assembly radially retract, and the rounding mechanism separates from the inner wall of the cylindrical workpiece; use the suspension mechanism to lift the cylindrical workpiece away from the workstation to complete the operation.

[0017] Preferably, in step S2, when the threaded shaft rotates, the first positioning terminal on the forward-rotating threaded section and the second positioning terminal on the reverse-rotating threaded section move towards each other, driving the first sector-type connecting rod assembly and the second sector-type connecting rod assembly to open radially synchronously; the sector-type connecting rod assemblies symmetrically arranged at both ends of the threaded shaft open synchronously with the rotation of the threaded shaft, and simultaneously perform diameter widening operations on the two openings of the cylindrical workpiece.

[0018] Preferably, in steps S2 and S5, the circumferential limiting component is a field pliers or clamp, which is clamped at the opening of the cylindrical workpiece, thereby limiting the circumferential rotation of the entire rounding mechanism relative to the cylindrical workpiece by blocking or limiting the rounding roller.

[0019] Preferably, in step S3, the axial limiter is a threaded sleeve fitted on the threaded shaft; after the fan-shaped connecting rod assembly is opened to the position, the threaded sleeve is rotated so that its end face abuts against the first positioning terminal and the second positioning terminal, locking the axial relative position of the positioning terminal and the threaded shaft, so that the rounding mechanism and the threaded shaft form a synchronously rotating whole.

[0020] Preferably, the entire process of widening the diameter to achieve a complete circle is carried out using a cold deformation process. The cylindrical workpiece is plastically deformed by pure mechanical force to achieve the widening of the diameter and the complete circle. There is no local heat input during the processing, and no additional heat treatment process is required after processing.

[0021] The present invention has the following beneficial effects: 1. The gantry frame of this invention adopts a detachable structural design, and each component can be disassembled for transportation and quickly assembled on site. By replacing crossbeams of different lengths and adjusting the adjustable length support rods, it can be adapted to workpieces such as pressure pipelines and cylindrical pressure vessels of various diameters. Field deployment can be completed without large machining equipment, and it is especially suitable for batch field operations of projects such as long-distance natural gas pipelines, pumped storage pressure pipelines, and large gas storage devices.

[0022] 2. This invention integrates two processes—fixed-point top pressing for rough rounding and circumferential roller pressing for fine rounding—through simple switching between circumferential and axial limiting. Rough rounding quickly eliminates large-size ellipticity and diameter deviations, while fine rounding ensures uniform roundness consistency across the entire circle. It eliminates the need for multiple machines and multiple processes; all rounding operations can be completed in a single clamping setup. Compared to traditional manual single-point correction processes, this invention improves work efficiency several times over.

[0023] 3. The present invention uses room temperature mechanical force to drive the workpiece to produce plastic deformation throughout the process, without local heat input, and will not introduce additional welding residual stress into the workpiece. After processing, there is no need for subsequent heat treatment processes such as annealing and tempering, which greatly simplifies the on-site construction process and reduces construction energy consumption and overall costs.

[0024] 4. This invention adopts a structure with forward and reverse spiral sections and multiple sets of fan-shaped connecting rod assemblies. When the threaded shaft rotates, each set of rounding rollers extends and retracts synchronously, and the thrust is evenly distributed along the circumference, avoiding excessive local stress on the workpiece and causing deformation damage. The rounding mechanism is symmetrically arranged at both ends of the threaded shaft, which can process the two openings of the workpiece simultaneously, further improving the efficiency of batch operation.

[0025] 5. This invention only requires controlling the forward and reverse rotation of the motor and the disassembly and assembly of the limit components to complete all processes. No complicated operating skills are required. On-site workers can operate independently after simple training, which effectively reduces labor costs and operating thresholds and is suitable for the skill conditions of personnel on the engineering site.

[0026] 6. The pipe ends processed by this device have high roundness and good diameter consistency, which can significantly reduce the difficulty of on-site assembly, improve the assembly accuracy and welding quality of the welding interface, and avoid welding defects such as misalignment and incomplete penetration caused by non-round pipe ends, thus ensuring the long-term operational safety of pressure vessels and pressure pipelines from the source. Attached Figure Description

[0027] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0028] Figure 1 This is a front view of the overall structure of the present invention.

[0029] Figure 2 This is a side view of the fan-shaped connecting rod assembly of the present invention.

[0030] Figure 3 To find the structural diagram of the circular roller for this invention.

[0031] In the diagram: 1. Gantry frame; 2. Motor; 3. Gearbox; 4. Coupling; 5. Cylindrical workpiece; 6. Suspension mechanism; 7. Fixing mechanism; 8. Rounding mechanism; 9. Threaded shaft; 101. Crossbeam; 102. Diagonal brace; 103. Support column; 601. Lifting hoist; 602. Hanging cable; 701. Adjustable length support rod; 702. Roller; 703. Fixed shaft; 801. Rounding roller; 801a. Roller bracket; 801b. Roller support rod; 801c. Hinge support; 801d. Hinge shaft; 801e. Support rod; 802. First positioning terminal; 803. Second positioning terminal; 804. First sector-type connecting rod assembly; 805. Second sector-type connecting rod assembly; 806. Detailed Implementation

[0032] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings and multiple embodiments. The described embodiments are only some implementations of the present invention, and not all implementations. Based on the technical solutions of the present invention, all other implementations obtained by those skilled in the art without creative effort are within the protection scope of the present invention.

[0033] Example 1: See Figure 1-3 A wide-diameter roundness finding machine for auxiliary on-site assembly and welding is disclosed. To meet the needs of on-site disassembly, transportation, and rapid assembly, and to provide a stable load-bearing base for the entire equipment, a prefabricated gantry structure is adopted. The gantry 1 includes a crossbeam 101, two supports 103, and a base; the lower end of each support 103 is detachably connected to the base, and the upper end is detachably connected to the crossbeam 101; diagonal braces 102 are provided between the support 103 and the crossbeam 101. This structure adopts a modular disassembly design, allowing for the adaptation of various pipe diameters by replacing crossbeams of different lengths. The diagonal braces form a triangular force-bearing system to ensure overall rigidity, combining portability and structural stability, making it suitable for deployment scenarios in the field where large hoisting equipment is unavailable.

[0034] Furthermore, to adapt to the different torque and speed requirements of the two working conditions of wide-diameter top pressing and roll forming, and to ensure stable and controllable power output, a symmetrical drive mechanism is set up. A pair of drive mechanisms are installed on both sides of the gantry 1. The drive mechanism includes a motor 2 and a gearbox 3; the output end of the motor 2 is connected to the input end of the gearbox 3, and the output shaft of the gearbox 3 is connected to a threaded shaft 9 via a coupling 4. The gearbox reduces speed and increases torque, outputting a large top thrust to meet the cold diameter expansion requirements. The symmetrical drive on both sides ensures that the threaded shaft 9 is subjected to balanced force without off-center load. The coupling facilitates quick assembly and disassembly of the threaded shaft and the drive end, improving on-site assembly efficiency.

[0035] Furthermore, to facilitate convenient hoisting and positioning of cylindrical workpieces and adjust the workstation height and position, adapting to the alignment requirements of workpieces of different lengths, a suspension mechanism is installed. A suspension mechanism 6 for suspending the cylindrical workpiece 5 is installed on the top of the gantry frame 1; the suspension mechanism 6 includes a hoist 601 and a hanging cable 602; the hoist 601 is slidably mounted on the crossbeam 101 of the gantry frame 1, and the hanging cable 602 is connected to the lower end of the hoist 601 for suspending the cylindrical workpiece 5. The hoist can slide along the crossbeam to adjust the hoisting position, and the hanging cable adapts to the hoisting requirements of workpieces with different outer diameters, independently completing workpiece lifting and circumferential angle adjustment without the need for additional hoisting equipment, thus lowering the threshold for on-site operations.

[0036] Furthermore, to radially limit the suspended cylindrical workpiece, determine the rotation reference, and ensure the coaxiality of the workpiece and the threaded shaft, an adjustable rolling support fixing mechanism is provided. A fixing mechanism 7 for radially positioning and supporting the rotation of the cylindrical workpiece 5 is fixed to the top of the gantry frame 1. The fixing mechanism 7 includes an adjustable length support rod 701, a fixed shaft 703, and a roller 702. The adjustable length support rod 701 is installed on the gantry frame 1, the fixed shaft 703 is located at the end of the adjustable length support rod 701, and the roller 702 is rotatably fitted onto the fixed shaft 703 to abut against and support the outer wall of the cylindrical workpiece 5. By adjusting the extension length of the support rod, workpieces of different diameters can be adapted. The roller adopts a rolling contact form, which both limits the radial offset of the workpiece to ensure coaxial accuracy and allows the workpiece to rotate circumferentially to adjust the top pressure angle, providing stable support and low rotational resistance.

[0037] Furthermore, to achieve multi-point synchronous diameter shaping of the pipe opening and ensure uniform circumferential force and consistent deformation, an umbrella-shaped fan-rib type connecting rod transmission structure is set. A rounding mechanism 8 is mounted on the threaded shaft 9; the rounding mechanism 8 includes multiple sets of fan-rib type connecting rod assemblies; each set of fan-rib type connecting rod assemblies includes a rounding roller 801, a support rod 802, and a positioning terminal; the positioning terminal is threadedly engaged with the threaded shaft 9; the two ends of the support rod 802 are respectively hinged to the positioning terminal and the rounding roller 801; multiple sets of fan-rib type connecting rod assemblies are distributed circumferentially along the threaded shaft 9, forming a radially openable umbrella-shaped structure; the rounding mechanism 8 includes at least two pairs of fan-rib type connecting rod assemblies, each pair including a first fan-rib type connecting rod assembly 805 and a second fan-rib type connecting rod assembly 806; the first positioning terminal 803 of the first fan-rib type connecting rod assembly 805 and the second positioning terminal 804 of the second fan-rib type connecting rod assembly 806 have opposite internal thread directions, respectively engaging with the forward-rotating thread section and the reverse-rotating thread section of the threaded shaft 9. When the threaded shaft rotates, the two positioning terminals in the forward and reverse directions move axially in opposite directions, driving the circumferential connecting rods to expand and contract radially in sync, achieving multi-point uniform pressure on the pipe wall, avoiding uneven local deformation caused by single-point force application, and ensuring good consistency of diameter and roundness.

[0038] Furthermore, to simultaneously complete the rounding operation at both ends of the workpiece, improve batch processing efficiency, and ensure synchronized deformation of the two ends, a double-sided symmetrical threaded drive structure is set up. Both ends of the threaded shaft 9 are symmetrically equipped with a forward-rotating thread section and a reverse-rotating thread section, enabling the symmetrically arranged fan-shaped connecting rod assemblies on both sides to open or close synchronously during the rotation of the threaded shaft 9. The rotation of a single threaded shaft can synchronously drive the rounding mechanisms at both ends to operate simultaneously, ensuring that the diameter and opening / closing speed of the two ends are completely consistent. This eliminates the need for separate processing at each end, significantly shortening the processing time for a single workpiece and improving batch processing efficiency.

[0039] Furthermore, to achieve rapid switching between the wide-diameter rough rounding and roll forming finishing modes, improve process integration, and simplify on-site operation, a combined limiting mechanism is set up. The rounding mechanism 8 also includes a circumferential limiting component and an axial limiting device; an axial limiting device is installed between the positioning terminal and the threaded shaft 9; the circumferential limiting component is clamped at the pipe opening position of the cylindrical workpiece 5 using on-site pliers or clamps, thereby limiting the overall circumferential rotation of the rounding mechanism 8 relative to the cylindrical workpiece 5; the axial limiting device is a threaded sleeve fitted on the threaded shaft 9, which locks the corresponding first positioning terminal 803 and second positioning terminal 804 through the threaded sleeve after the fan-shaped connecting rod assembly is opened to the position, thereby making the threaded shaft 9 and the rounding mechanism 8 form an integral whole. When the circumferential degree of freedom is locked, the rotation of the threaded shaft is converted into the radial tension and contraction of the connecting rod to perform fixed-point diameter expansion operation; when the axial degree of freedom is locked and the circumferential degree of freedom is released, the rounding mechanism rotates with the threaded shaft as a whole to perform circumferential rolling operation; the switching of working conditions only requires disassembling and assembling the limiting parts, without disassembling the main structure, and the operation is simple and adaptable to the on-site working conditions.

[0040] Furthermore, to reduce frictional resistance during roller pressing, minimize pipe wall wear, and ensure flexible hinged transmission and sufficient structural rigidity, the split structure of the rounding roller is optimized. The rounding roller 801 includes a roller bracket 801a, a roller support rod 801b, a roller body 801c, a hinge support 801d, and a hinge shaft 801e. The roller support rod 801b is mounted on the roller bracket 801a, and the roller body 801c is rotatably mounted on the roller bracket 801a. The roller bracket 801a is mounted on the hinge support 801d, which is hinged to the support rod 802 via the hinge shaft 801e. The roller body adopts a rolling contact form, rolling along the pipe wall without sliding friction during roller pressing, thus avoiding scratching the inner wall of the workpiece. The hinge shaft, in conjunction with the support, ensures smooth and unobstructed extension and retraction of the connecting rod. The roller support rod enhances the overall load-bearing capacity, capable of withstanding large-diameter working loads with high thrust.

[0041] Working principle of the invention: This invention is based on the principle of lead screw and nut transmission and the mechanism of cold plastic deformation. It integrates the roughing and finishing rounding processes by switching the working conditions of the limiting mechanism. The specific principle is as follows: 1. Radial telescopic drive principle: The threaded shaft 9 is provided with a forward-rotating thread segment and a reverse-rotating thread segment with opposite directions of rotation, which respectively engage with the first positioning terminal 803 and the second positioning terminal 804. When the circumferential limiting component restricts the overall circumferential rotation of the rounding mechanism 8, the positioning terminals cannot rotate synchronously with the threaded shaft 9, converting the rotational motion of the threaded shaft 9 into the axial linear motion of the two positioning terminals; when the two positioning terminals move towards each other, the support rod 802 pushes each set of rounding rollers 801 to open synchronously in the radial direction, applying a uniform radial force to the inner wall of the cylindrical workpiece 5; when the two positioning terminals move away from each other, the fan-shaped connecting rod assembly retracts radially, realizing demolding.

[0042] 2. Dual-condition switching principle: Through the cooperation of the circumferential limiting component and the axial limiting device, the two working conditions of wide diameter and rounding are quickly switched. In the rough rounding condition, the circumferential limiting component locks the circumferential rotation, and the rotation of the threaded shaft 9 only drives the connecting rod to extend and retract radially, realizing fixed-point pressing of the wide diameter, which is used to eliminate large-size ovality and diameter deviation; in the finishing rounding condition, the axial limiting device locks the axial relative position of the positioning terminal and the threaded shaft 9. After the circumferential limiting is released, the threaded shaft 9 drives the entire rounding mechanism 8 to rotate synchronously, and the rounding roller 801 continuously rolls and presses along the inner wall of the workpiece in the circumferential direction, realizing uniform shaping of the whole circle and improving the roundness consistency.

[0043] 3. Workpiece positioning and support principle: The suspension mechanism 6 realizes the hoisting and positioning of the cylindrical workpiece 5 and the height adjustment. The fixing mechanism 7 adjusts the support position through the adjustable length support rod 701, and the roller 702 forms rolling support on the outer wall of the workpiece. This ensures that the rotation axis of the workpiece is coaxial with the thread shaft 9, providing a stable rotation reference for the roll pressing operation, and also allows the workpiece to rotate circumferentially to adjust the top pressing angle.

[0044] The complete operation process of the wide-diameter roundness finding machine described in this invention is divided into five stages: station setup, rough roundness finding, working condition switching, fine roundness finding, and demolding and unloading. The specific working process is as follows: 1. Workstation Setup and Clamping Positioning: Based on the diameter and length of the cylindrical workpiece 5 to be processed, assemble the base, support column 103, and crossbeam 101 of the gantry frame 1 on site, and install diagonal braces 102 to ensure structural rigidity; symmetrically install motors 2 and gearboxes 3 at both ends of the gantry frame 1, connect the threaded shaft 9 through couplings 4, and pre-install the rounding mechanism 8 at the corresponding pipe opening position of the threaded shaft 9. Use the hoist 601 and hanging cable 602 to suspend the cylindrical workpiece 5 to the working height, adjust the extension length of the adjustable length support rods 701 on both sides to ensure that the roller 702 stably abuts against the outer wall of the workpiece, calibrate the workpiece axis to be coaxial with the threaded shaft 9, and complete the clamping and positioning.

[0045] 2. Fixed-point pressing for rough rounding: On-site pliers or clamps are used as circumferential limiting components, clamping the cylindrical workpiece 5 at the pipe opening to restrict the circumferential rotation of the rounding roller 801 and the entire rounding mechanism 8. The motor 2 is started and rotates forward, driving the threaded shaft 9 to rotate after being reduced in speed and torque by the gearbox 3. The first positioning terminal 803 and the second positioning terminal 804 move axially towards each other, causing each set of fan-shaped connecting rod assemblies to open radially synchronously. The rounding roller 801 evenly presses against the inner wall of the pipe opening, causing plastic deformation at room temperature, gradually expanding the diameter to the preset target value. After the pressure is held for a set time to allow the deformation to stabilize sufficiently, the motor 2 reverses, driving the positioning terminals to move in opposite directions, causing the fan-shaped connecting rod assemblies to retract radially, and the rounding roller 801 detaches from the inner wall of the workpiece. The cylindrical workpiece 5 is rotated slightly by the suspension mechanism 6, and the pressing angle is changed. The above opening-holding-retraction cycle is repeated. After multiple operations, the large ovality and diameter deviation of the pipe opening are eliminated, completing the rough rounding.

[0046] 3. Axial Locking and Operating Condition Switching: After the last fan-shaped connecting rod assembly opens to the target diameter, rotate the threaded sleeve-type axial limiter fitted on the threaded shaft 9, so that its end face abuts against the first positioning terminal 803 and the second positioning terminal 804, locking the axial relative position of the positioning terminals and the threaded shaft 9 to prevent the connecting rod from radially retracting during subsequent rotation. Remove the circumferential limiting fixture, release the circumferential rotation constraint of the rounding mechanism 8, and complete the operating condition switching.

[0047] 4. Circumferential Rolling Finishing: The starting motor 2 drives the threaded shaft 9 and the entire rounding mechanism 8 to rotate coaxially at a uniform speed. Under a constant clamping force, the rounding roller 801 continuously rolls along the inner wall of the pipe opening, uniformly rolling and shaping the entire pipe wall to further correct local roundness errors and improve the roundness consistency of the entire pipe opening. After the set rolling time, the machine stops, completing the finishing rounding operation.

[0048] 5. Demolding and workpiece unloading: Reinstall the circumferential limiting assembly to restrict the circumferential rotation of the rounding mechanism 8, remove the axial limiter, and control the motor 2 to reverse so that the fan-shaped connecting rod assembly radially retracts to its minimum diameter, completely separating the rounding mechanism 8 from the inner wall of the cylindrical workpiece 5. Release the hanging cable 602, and use the hoist 601 to lift the processed cylindrical workpiece 5 away from the workstation, completing a single operation. For workpieces of the same batch and specifications, there is no need to repeatedly adjust the gantry 1 and the fixing mechanism 7; repeating the above steps can achieve continuous batch processing.

[0049] Example 2: This embodiment provides a method for finding the wide diameter circle for assisting on-site assembly welding, including the following steps: S1, Workstation setup and workpiece positioning: Assemble the gantry frame 1, install the drive mechanism in pairs on both sides of the gantry frame 1, and connect the threaded shaft 9 through the coupling 4; suspend the cylindrical workpiece 5 to the workstation through the suspension mechanism 6, adjust the fixing mechanism 7 to radially position the cylindrical workpiece 5 and determine its rotation axis; fit the rounding mechanism 8 onto the threaded shaft 9 at the position corresponding to the pipe opening of the cylindrical workpiece 5. S2, Radial Expansion and Rough Rounding: Activate the circumferential limiting component to restrict the circumferential rotation of the umbrella-shaped structure relative to the cylindrical workpiece 5; start the drive mechanism to drive the threaded shaft 9 to rotate, drive the positioning terminal to move axially along the threaded shaft 9, so that each set of fan-shaped connecting rod assemblies opens radially, and the rounding roller 801 presses against the inner wall of the cylindrical workpiece 5 to achieve cold expansion; after holding the pressure for a set time, reverse the drive of the threaded shaft 9 to make the fan-shaped connecting rod assemblies radially retract; adjust the circumferential angle of the cylindrical workpiece 5, and repeat the above opening, holding, and retracting actions to complete the rough rounding; S3, Axial Locking and Operating Condition Switching: After the fan-shaped connecting rod assembly opens to the target diameter for the last time, install the axial limiter to lock the axial relative movement between the positioning terminal and the threaded shaft 9; release the circumferential limit assembly from restricting the circumferential rotation of the umbrella-shaped structure. S4, Circumferential Roller Finishing Round: Start the drive mechanism to drive the threaded shaft 9 and the rounding mechanism 8 to rotate coaxially. The rounding roller 801 continuously rolls and rolls along the inner wall of the cylindrical workpiece 5 to uniformly shape the entire circumference of the tube opening and complete the finishing round. S5, Demolding and workpiece removal: After stopping the machine, reactivate the circumferential limiting component, remove the axial limiting device, reverse drive the threaded shaft 9 to make the fan-shaped connecting rod assembly radially retract, and the rounding mechanism 8 separates from the inner wall of the cylindrical workpiece 5; lift the cylindrical workpiece 5 away from the work station through the suspension mechanism 6 to complete the operation.

[0050] Furthermore, in step S2, when the threaded shaft 9 rotates, the first positioning terminal 803 on the forward thread section and the second positioning terminal 804 on the reverse thread section move towards each other, driving the first sector-type connecting rod assembly 805 and the second sector-type connecting rod assembly 806 to open radially in sync. The sector-type connecting rod assemblies symmetrically arranged at both ends of the threaded shaft 9 open synchronously with the rotation of the threaded shaft 9, and simultaneously perform diameter widening operations on the two openings of the cylindrical workpiece 5.

[0051] Furthermore, in steps S2 and S5, the circumferential limiting component uses field pliers or clamps to clamp the tube opening of the cylindrical workpiece 5, thereby restricting the overall circumferential rotation of the rounding mechanism 8 relative to the cylindrical workpiece 5 by blocking or limiting the rounding roller 801.

[0052] Furthermore, in step S3, the axial limiter is a threaded sleeve fitted on the threaded shaft 9; after the fan-shaped connecting rod assembly is opened to the position, the threaded sleeve is rotated so that its end face abuts against the first positioning terminal 803 and the second positioning terminal 804, locking the axial relative position of the positioning terminal and the threaded shaft 9, so that the rounding mechanism 8 and the threaded shaft 9 form a synchronously rotating whole.

[0053] Furthermore, the entire process of widening the diameter to achieve a complete circle adopts a cold deformation process. The cylindrical workpiece 5 is plastically deformed by pure mechanical force to achieve the widening diameter and the complete circle. There is no local heat input during the processing, and no additional heat treatment process is required after processing.

[0054] It should be noted that the above examples are merely specific embodiments of the present invention, and the present invention is not limited to these embodiments. All similar variations related to these embodiments are within the protection scope of the present invention. All modifications that can be directly derived or conceived by those skilled in the art from the disclosure of the present invention should fall within the protection scope of the present invention.

Claims

1. A wide-diameter roundness finding machine for assisting on-site assembly welding, characterized in that, The system includes a gantry frame (1), with drive mechanisms installed in pairs on both sides of the gantry frame (1). The output shaft of the drive mechanism is connected to a threaded shaft (9) via a coupling (4). A suspension mechanism (6) for suspending a cylindrical workpiece (5) is installed on the top of the gantry frame (1). A fixing mechanism (7) for radially positioning the cylindrical workpiece (5) and supporting its rotation is fixed on the top of the gantry frame (1). A rounding mechanism (8) is fitted on the threaded shaft (9). The rounding mechanism (8) includes multiple sets of fan-shaped connecting rod assemblies, circumferential limiting assemblies, and axial limiting devices. Each set of fan-shaped connecting rod assemblies includes a rounding roller (801), a support rod (802), and a positioning terminal. The positioning terminal is threadedly engaged with the threaded shaft (9), and the positioning terminal is fitted with an axial limiting device. The two ends of the support rod (802) are respectively hinged to the positioning terminal and the rounding roller (801). Multiple sets of fan-shaped connecting rod assemblies are distributed circumferentially along the threaded shaft (9) to form a radially openable umbrella-shaped structure. The circumferential limiting component selectively restricts the circumferential rotation of the umbrella-shaped structure relative to the cylindrical workpiece (5); when the circumferential limiting component restricts the circumferential rotation, the drive mechanism drives the threaded shaft (9) to rotate, drives the positioning terminal to move axially, and causes the fan-shaped connecting rod assembly to open radially to achieve wide diameter rounding; when the circumferential limiting component releases the circumferential rotation restriction, the axial limiter locks the axial movement between the positioning terminal and the threaded shaft (9), and the drive mechanism drives the threaded shaft (9) and the rounding mechanism (8) to rotate as a whole, and the rounding roller (801) rolls along the inner wall of the cylindrical workpiece (5) to achieve roller rounding and complete rounding.

2. The wide-diameter roundness finding machine for auxiliary on-site assembly welding according to claim 1, characterized in that, The gantry frame (1) includes a crossbeam (101), two support columns (103) and a base; the lower end of the support column (103) is detachably connected to the base and the upper end is detachably connected to the crossbeam (101); a diagonal brace (102) is provided between the support column (103) and the crossbeam (101).

3. The wide-diameter roundness finding machine for auxiliary on-site assembly welding according to claim 1, characterized in that, The drive mechanism includes a motor (2) and a gearbox (3); the output end of the motor (2) is connected to the input end of the gearbox (3), and the output end of the gearbox (3) is coaxially connected to the threaded shaft (9) through a coupling (4).

4. The wide-diameter roundness finding machine for auxiliary on-site assembly welding according to claim 1, characterized in that, The suspension mechanism (6) includes a hoist (601) and a hanging cable (602); the hoist (601) is slidably mounted on the crossbeam (101) of the gantry frame (1), and the hanging cable (602) is connected to the lower end of the hoist (601) for lifting cylindrical workpieces (5).

5. The wide-diameter roundness finding machine for auxiliary on-site assembly welding according to claim 1, characterized in that, The fixing mechanism (7) includes an adjustable length support rod (701), a fixed shaft (703) and a roller (702); the adjustable length support rod (701) is installed on the gantry (1), the fixed shaft (703) is located at the end of the adjustable length support rod (701), and the roller (702) is rotatably fitted onto the fixed shaft (703) to abut against and support the outer wall of the cylindrical workpiece (5).

6. The wide-diameter roundness finding machine for auxiliary on-site assembly welding according to claim 1, characterized in that, The round-finding mechanism (8) includes at least two pairs of sector-type connecting rod assemblies, each pair including a first sector-type connecting rod assembly (805) and a second sector-type connecting rod assembly (806); the first positioning terminal (803) of the first sector-type connecting rod assembly (805) and the second positioning terminal (804) of the second sector-type connecting rod assembly (806) have opposite internal thread directions, respectively cooperating with the forward-rotating thread section and the reverse-rotating thread section of the threaded shaft (9).

7. A wide-diameter roundness finding machine for auxiliary on-site assembly welding according to claim 6, characterized in that, Both ends of the threaded shaft (9) are symmetrically provided with a forward thread section and a reverse thread section, so that the fan-shaped connecting rod assemblies arranged symmetrically on both sides can be opened or closed synchronously during the rotation of the threaded shaft (9).

8. A wide-diameter roundness finding machine for auxiliary on-site assembly welding according to claim 6, characterized in that, The circumferential limiting component is clamped at the opening of the cylindrical workpiece (5) using pliers or clamps on site, thereby restricting the overall circumferential rotation of the rounding mechanism (8) relative to the cylindrical workpiece (5).

9. A wide-diameter roundness finding machine for auxiliary on-site assembly welding according to claim 6, characterized in that, The axial limiter uses a threaded sleeve fitted on the threaded shaft (9). After the fan-shaped connecting rod assembly is opened to the position, the threaded sleeve locks the corresponding first positioning terminal (803) and second positioning terminal (804), thereby making the threaded shaft (9) and the rounding mechanism (8) form a whole.

10. A wide-diameter roundness finding machine for auxiliary on-site assembly welding according to claim 1, characterized in that, The rounding roller (801) includes a roller bracket (801a), a roller support rod (801b), a roller body (801c), a hinge support (801d), and a hinge shaft (801e); the roller support rod (801b) is mounted on the roller bracket (801a), and the roller body (801c) is rotatably mounted on the roller bracket (801a); the roller bracket (801a) is mounted on the hinge support (801d), and the hinge support (801d) is hinged to the support rod (802) through the hinge shaft (801e).

11. A method for finding the wide-diameter circle for assisting on-site assembly welding, characterized in that, The wide-diameter roundness finding machine for auxiliary on-site assembly welding as described in any one of claims 1-10 is adopted. Includes the following steps: S1, Workstation setup and workpiece placement: Assemble the gantry (1), install drive mechanisms in pairs on both sides of the gantry (1), and connect the threaded shaft (9) through the coupling (4); suspend the cylindrical workpiece (5) to the workstation through the suspension mechanism (6), adjust the fixing mechanism (7) to radially position the cylindrical workpiece (5) and determine its rotation axis; fit the rounding mechanism (8) onto the threaded shaft (9) at the position corresponding to the opening of the cylindrical workpiece (5); S2, Radial Expansion Rough Rounding: Activate the circumferential limiting component to restrict the circumferential rotation of the umbrella-shaped structure relative to the cylindrical workpiece (5); start the drive mechanism to drive the threaded shaft (9) to rotate, drive the positioning terminal to move axially along the threaded shaft (9), so that each set of fan-shaped connecting rod assemblies opens radially, and the rounding roller (801) presses against the inner wall of the cylindrical workpiece (5) to achieve cold expansion; after holding pressure for a set time, reverse drive the threaded shaft (9) to make the fan-shaped connecting rod assembly radially close; adjust the circumferential angle of the cylindrical workpiece (5), repeat the above opening, holding pressure and closing actions to complete the rough rounding; S3, Axial Locking and Working Condition Switching: After the fan-shaped connecting rod assembly opens to the target diameter for the last time, install the axial limiter to lock the axial relative movement between the positioning terminal and the threaded shaft (9); release the circumferential limit assembly from restricting the circumferential rotation of the umbrella-shaped structure; S4, Circumferential Roller Press Finishing Circle: Start the drive mechanism to drive the threaded shaft (9) and the rounding mechanism (8) to rotate coaxially as a whole. The rounding roller (801) continuously rolls and presses along the inner wall of the cylindrical workpiece (5) to uniformly shape the entire tube opening and complete the finishing circle; S5, Demolding and workpiece removal: After stopping the machine, reactivate the circumferential limiting component, remove the axial limiting device, reverse drive the threaded shaft (9) to make the fan-shaped connecting rod assembly radially close, and the rounding mechanism (8) separates from the inner wall of the cylindrical workpiece (5); lift the cylindrical workpiece (5) away from the work station through the suspension mechanism (6) to complete the operation.

12. The method for finding the wide-diameter circle for auxiliary on-site assembly welding according to claim 11, characterized in that, In step S2, when the threaded shaft (9) rotates, the first positioning terminal (803) on the forward thread section and the second positioning terminal (804) on the reverse thread section move towards each other, driving the first sector-type connecting rod assembly (805) and the second sector-type connecting rod assembly (806) to open radially in sync. The sector-type connecting rod assemblies symmetrically arranged at both ends of the threaded shaft (9) open synchronously with the rotation of the threaded shaft (9), and simultaneously perform diameter widening operations on the two openings of the cylindrical workpiece (5).

13. The method for finding the wide-diameter circle for auxiliary on-site assembly welding according to claim 11, characterized in that, In steps S2 and S5, the circumferential limiting component is clamped at the opening of the cylindrical workpiece (5) using field pliers or clamps, thereby limiting the circumferential rotation of the rounding mechanism (8) relative to the cylindrical workpiece (5) by blocking or limiting the rounding roller (801).

14. The method for finding the wide-diameter circle for auxiliary on-site assembly welding according to claim 11, characterized in that, In step S3, the axial limiter is a threaded sleeve fitted on the threaded shaft (9); after the fan-shaped connecting rod assembly is opened to the position, the threaded sleeve is rotated so that its end face abuts against the first positioning terminal (803) and the second positioning terminal (804), locking the axial relative position of the positioning terminal and the threaded shaft (9), so that the rounding mechanism (8) and the threaded shaft (9) form a synchronous rotating whole.

15. The method for finding the wide-diameter circle for auxiliary on-site assembly welding according to claim 11, characterized in that, The entire process of finding the wide diameter and the circle adopts cold deformation processing technology. The cylindrical workpiece (5) is plastically deformed by pure mechanical force to achieve the wide diameter and the circle. There is no local heat input during the processing, and no additional heat treatment process is required after processing.

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