Welding method for folding of stand column ports

Abstract

The invention discloses a welding method for folding upright post ports, which comprises the following steps of: hoisting an upper-layer deck piece, and assembling and folding welded junctions at the free ends of a first upright post of the upper-layer deck piece and a second upright post of a lower-layer deck piece; folding openings of the first stand column and the second stand column adopt an inner groove and an outer groove which are asymmetric, and the inner grooves of the first stand column and the second stand column are welded by adopting a manual gas shielded welding process; the outer grooves of the first stand column and the second stand column are subjected to manual gas shielded welding through a welding gun, so that the outer grooves form a first layer of welding bead; a hard rail is connected below the folding opening of the second stand column, so that the welding trolley moves along the hard rail; and the welding gun is fixed to the welding trolley through the quick clamping connector, and the welding trolley is started, so that the welding gun forms a second layer of welding bead along the first layer of welding bead of the outer groove in a surfacing mode. According to the welding method for folding the stand column ports, the construction quality is improved, safety and reliability are achieved, and efficiency is high.

Description

Technical Field

[0001] This invention belongs to the field of marine oil engineering, and in particular relates to a welding method for closing the ends of a column. Background Technology

[0002] Offshore oil platforms are core equipment in marine engineering, and the main column is the key load-bearing structure of the entire modular platform. During onshore construction, depending on the equipment capabilities of the construction site, the platform is often prefabricated in several layers of deck panels, which are then hoisted into place layer by layer. The main key node for assembling the upper and lower deck panels is the assembly of the main column.

[0003] The main columns of offshore oil platforms are typically about 2 meters in diameter with a wall thickness of 50-90 mm. Welding them is a massive undertaking, requiring significant manpower and equipment, resulting in low efficiency and inconsistent quality. While automated welding trolleys have been gradually applied in marine engineering steel structure welding, they are mainly used on auxiliary structures such as decks and wall panels. During the final assembly stage, when the main structure is joined, various processing errors lead to uneven bevels, inconsistent angles and gaps. Therefore, automated welding lacks practical experience, and manual welding is still necessary, with parameters adjusted in real-time to eliminate these unevennesses.

[0004] The following problems exist during the welding of the main column closure joint: 1. The upper and lower deck structures of offshore platforms are large in tonnage and size. During the assembly of the columns, accumulated errors necessitate re-refining, disrupting the uniformity of the bevel. Combined with deviations in the ellipticity of the columns themselves and the cumulative errors in processing precision, the resulting gaps, misalignments, and bevel angles exceed the tolerance range of automated welding. Therefore, fully implementing automated welding is not feasible; manual welding is the only option, requiring adjustments to parameters such as current, voltage, and welding speed during the process to compensate for and eliminate bevel unevenness. 2. The space at the main column closure position is narrow. Currently, the commonly used automatic welding trolleys generally use soft tracks, making it difficult to arrange the welding trolleys. The magnetic attraction of the trolleys is not strong and they are prone to deviating downwards, making them unsuitable for construction scenarios involving welding of the main structure. 3. Manual welding results in low work efficiency, high labor intensity, and unstable weld quality, making it unable to meet project requirements.

[0005] Therefore, there is an urgent need to design a welding method for closing the column ends to solve the problems mentioned above. Summary of the Invention

[0006] To address the technical problems mentioned in the background art, such as the need for re-refining the bevel due to accumulated errors during column assembly, which disrupts the uniformity of the bevel, and the low work efficiency and high labor intensity caused by manual welding, a welding method for closing the column ends is provided to solve the problem of column end closure.

[0007] To achieve the above objectives, the specific technical solution of the welding method for closing the column ends of the present invention is as follows: A welding method for closing the ends of a column mainly includes the following steps: S1. Hoist the upper deck section and assemble the weld joints at the free ends of the first column of the upper deck section and the second column of the lower deck section. S2. The joint between the first column and the second column adopts an asymmetrical inner bevel and outer bevel form. The inner bevel of the first column and the second column is welded using a manual gas shielded welding process. S3. Perform manual gas shielded welding on the outer bevels of the first and second columns using a welding torch to form the first weld bead on the outer bevels. S4. Connect a rigid track below the second column's closure opening to allow the welding trolley to move along the rigid track; S5. Use the quick clamping connector to fix the welding torch on the welding carriage, start the welding carriage, so that the welding torch can build up the first layer of weld along the outer bevel to form the second layer of weld. S6. Remove the welding torch from the quick-clamping connector and repair the second weld bead using manual gas shielded welding mode.

[0008] Furthermore, in S2, the depth of the inner bevel is less than that of the outer bevel.

[0009] Furthermore, in S4, a rigid track is connected circumferentially to the second column so that the rigid track is arranged around the outer wall of the second column.

[0010] Furthermore, in S5, the second layer of weld is welded using the first-pass positioning method. Starting from the first pass of the second layer of weld, a fixed angle and parameters are used until the last pass of the second layer of weld without any adjustments in between, thereby accumulating the bevel error to the end.

[0011] Furthermore, in S6, the gap between the second weld bead and the first and second columns is repaired by welding so that the second weld bead is level with the outer walls of the first and second columns.

[0012] Furthermore, after the second layer of weld is completed, the welding torch is placed on the quick-clamping joint, and the welding carriage is used to build up the weld cover along the second layer of weld.

[0013] The welding method for closing the column ends of the present invention has the following advantages: Stable operation of the welding trolley was achieved through a rigid track, and rapid switching between manual and automatic welding was realized through quick-clamping joints. This combined the advantages of both manual and automatic welding, and the first-pass positioning method expanded the adaptability of automatic welding. This marked the first application of automatic welding in the welding of the main column closure joint of a large steel structure offshore oil platform during the deck assembly stage. This application improves the construction efficiency and quality of main column welding, ensuring safety, reliability, and high efficiency. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the welding method for closing the column ends of the present invention, showing the assembly of the upper and lower deck plates; Figure 2 This is a schematic diagram of the welding method for closing the column ends of the present invention, showing the assembly of the first and second columns. Figure 3 This is a schematic diagram of the welding method for closing the column ends of the present invention, showing the welding of the inner and outer bevels. Figure 4 This is a schematic diagram of the welding trolley arrangement for the welding method of closing the column ends of the present invention; Figure 5 This is a schematic diagram of the first positioning method of the second layer of weld in the welding method for closing the column end of the present invention.

[0015] Explanation of markings in the diagram: 1. Upper deck plate; 2. Lower deck plate; 3. First column; 4. Second column; 5. Inner bevel; 6. Outer bevel; 7. Welding torch; 8. Quick clamping connector; 9. Welding carriage; 10. Rigid rail. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] Those skilled in the art will understand that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of the invention and form different embodiments. For example, in the claims, any of the claimed embodiments can be used in any combination.

[0018] The following is a reference to the appendix. Figure 1 To be continued Figure 5 The present invention describes a welding method for closing the column ends.

[0019] The welding method for closing the column ends in this invention mainly includes the following steps: S1. The upper deck section 1 and the lower deck section 2 of the offshore oil and gas platform are prefabricated in the workshop, with each having a reserved free end of the column. The upper deck section 1 is hoisted to assemble and close the weld joint of the first column 3 of the upper deck section 1 and the second column 4 of the lower deck section 2. S2. The closure of the first column 3 and the second column 4 adopts an asymmetrical inner bevel 5 and outer bevel 6 form. The inner bevels of the first column 3 and the second column 4 are welded using a manual gas shielded welding process. Among them, the depth of the inner bevel 5 is less than that of the outer bevel 6, and the opening angles of the inner bevel 5 and the outer bevel 6 are the same. S3. Manual gas shielded welding is performed on the outer bevels 6 of the first column 3 and the second column 4 using a welding gun 7 to form the first weld bead on the outer bevels 6. As a preferred embodiment, the first layer of weld bead is divided into multiple layers. Since the gap at the root of the outer bevel 6 is relatively narrow, manual welding can ensure the quality of the root. The construction worker holds the welding gun 7 and welds around the outer bevel 6 until the gap of the outer bevel 6 becomes wider. Then, the welding carriage 9 is used to weld the outer bevel 6.

[0020] S4. Connect the rigid rail 10 below the closing opening of the second column 4 so that the welding trolley 9 can move along the rigid rail 10. Among them, a rigid track 10 is connected around the second column 4 so that the rigid track 10 is arranged around the outer wall of the second column 4, and the overall spacing between the rigid track 10 and the closing opening is consistent, which facilitates the movement and welding of the welding trolley 9. S5. Use the quick clamping connector 8 to fix the welding torch 7 on the welding carriage 9, start the welding carriage 9, so that the welding torch 7 can build up the first layer of weld along the outer bevel 6 to form the second layer of weld. As a preferred embodiment, the second layer of weld bead has a multi-layer structure, that is, the welding carriage 9 welds along the first layer of weld bead at a point, and each layer of weld bead consists of multiple automatic weld beads. When multiple automatic weld beads have filled a layer, the next layer is automatically welded.

[0021] The quick-clamping connector 8 mounted on the welding trolley 9 allows for flexible and rapid switching between manual and automatic gas shielded welding throughout the welding process. This "manual-automatic" mode improves production efficiency and reduces labor intensity compared to purely manual welding. It solves the problem of not being able to use automatic welding during the column assembly stage due to uneven beveling and accumulated processing errors, expanding the applicability of automatic welding. Furthermore, the rigid track layout is simple, convenient, fast, and efficient.

[0022] The rigid track 10 prevents the welding trolley 9 from deviating due to gravity when it is moving, thus improving the construction quality and the efficiency of column closure welding. The second layer of weld is welded using the first-pass positioning method. Starting from the first pass of the second layer, a fixed angle and parameters are used until the last pass of the second layer, without any adjustments in between. This allows the error of the bevel to accumulate until the end. The first-pass positioning method greatly improves the adaptability of automatic welding, avoids the need for constant adjustments to adapt to uneven bevels, increases the utilization rate of the trolley, and compensates for the lack of flexibility in trolley welding, thus greatly improving production efficiency and weld quality.

[0023] S6. Remove the welding torch 7 from the quick-clamping connector 8 and repair the second weld bead using manual gas shielded welding mode. Specifically, the gap between the second weld bead and the first column 3 and the second column 4 is repaired by welding so that the second weld bead is level with the outer wall of the first column 3 and the second column 4. That is, after the first weld bead in the second weld bead is welded using the first positioning method, the uneven areas on both sides of the first weld bead are manually welded. Then, the next weld bead is welded on the first weld bead until the second weld bead is level with the outer wall of the first column 3 and the second column 4.

[0024] S7. After the second layer of weld is completed, the welding torch 7 is placed on the quick clamping joint 8, and the welding carriage 9 is used to build up the weld cover along the second layer of weld.

[0025] Based on the welding method for closing the column ends, this invention achieves stable operation of the welding trolley 9 through the rigid track 10 and enables rapid switching between manual and automatic welding through the quick-clamping joint 8. It integrates the advantages of manual and automatic welding, and expands the adaptability of automatic welding by combining the first-pass positioning method. This invention realizes the first application of automatic welding in the welding construction of the main column closing joint of a large steel structure offshore oil platform during the deck assembly stage, improving the construction efficiency and quality of main column welding. It is safe, reliable, and highly efficient.

[0026] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A welding method for closing the ends of a column, characterized in that, The main steps include: S1. Hoist the upper deck section and assemble the weld joints at the free ends of the first column of the upper deck section and the second column of the lower deck section. S2. The joint between the first column and the second column adopts an asymmetrical inner bevel and outer bevel form. The inner bevel of the first column and the second column is welded using a manual gas shielded welding process. S3. Perform manual gas shielded welding on the outer bevels of the first and second columns using a welding torch to form the first weld bead on the outer bevels. S4. Connect a rigid track below the second column's closure opening to allow the welding trolley to move along the rigid track; S5. Use the quick clamping connector to fix the welding torch on the welding carriage, start the welding carriage, so that the welding torch can build up the first layer of weld along the outer bevel to form the second layer of weld. S6. Remove the welding torch from the quick-clamping connector and repair the second weld bead using manual gas shielded welding mode.

2. The welding method for closing the column ends according to claim 1, characterized in that, In S2, the depth of the inner bevel is less than that of the outer bevel.

3. The welding method for closing the column ends according to claim 1, characterized in that, In S4, a rigid track is connected circumferentially to the second column so that the rigid track is arranged around the outer wall of the second column.

4. The welding method for closing the column ends according to claim 1, characterized in that, In S5, the second layer of weld is welded using the first-pass positioning method. Starting from the first pass of the second layer of weld, a fixed angle and parameters are used until the last pass of the second layer of weld without any adjustments in between, thus accumulating the error of the bevel to the end.

5. The welding method for closing the column ends according to claim 1, characterized in that, In S6, the gap between the second weld bead and the first and second columns is repaired by welding so that the second weld bead is level with the outer walls of the first and second columns.

6. The welding method for closing the column ends according to claim 5, characterized in that, After the second layer of weld is completed, the welding torch is set on the quick-clamping joint, and the welding carriage is used to build up the weld cover along the second layer of weld.

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