A method for closing a portal structure of a large crane

Abstract

The present application relates to the field of construction, disclose a kind of folding method of large crane portal structure: including the following steps: erecting and making jig frame;Welding support leg a, support leg b and cross beam;Assembling flange tooling;Welding support leg d and increasing fixed support;Welding ladder, platform is painted, then turns over 90 °;Remove flange tooling, install support leg d;Install large pin wheel support ring;Finally, the process bolt is replaced by formal bolt.The beneficial effects of the present application are that by providing flange tooling on the top of the support leg, due to the large size of the support leg, the flange tooling can stabilize and correct the top of the support leg, preventing accuracy problems caused by the large size, improving the accuracy of the support leg folding into a portal, using specific tooling to overcome site and lifting equipment limitations, ensuring installation accuracy, preventing unstable and abnormal noise conditions.

Description

Technical Field

[0001] This invention relates to the field of construction, specifically a method for assembling a large crane gantry structure. Background Technology

[0002] Because the support ring on the crane gantry is quite large, if the installation accuracy is low, the upper turntable of the crane will be unstable and produce abnormal noise when it rotates. Therefore, during installation, there are high requirements for the levelness between the support ring and the cross beam support plane on the crane gantry, as well as the distance between the center of the cross beam and the vertical line of the support ring.

[0003] Document CN201120047426 discloses a gantry crane spanning an arch rib, including a hoisting system, a steel structure main body, and a main traveling system. The steel structure main body is composed of two parallel connected gantry frames, each of which consists of a main beam and legs connected by a connecting frame. The steel structure main body is assembled using universal rods, and each main beam is equipped with two lifting trolleys that can move horizontally along the direction of the main beam. This installation method is prone to causing the steel structure main body to shift or tilt during hoisting, resulting in reduced installation accuracy in the later stages. Summary of the Invention

[0004] To address the aforementioned problems, this invention discloses a method for assembling a large crane gantry structure, which can effectively improve the installation accuracy of the crane gantry and prevent instability and abnormal noise.

[0005] The technical solution of this invention is: a method for assembling a large crane gantry structure, comprising the following steps: Step 1: Set up the fabrication frame. Based on the actual structure of the gantry, set up the fabrication frame at the fabrication site. The head and tail of the outriggers and the lower part of the cross beam are the main support points. Mark the ground line with the center line of the cross beam as the reference. Step 2: Install and weld support legs a, support legs b and cross beams, assemble the door legs and cross beams, check the upper and lower positioning dimensions of the support legs according to the ground line, fix the support legs and cross beams, and weld the joint between them. Step 3: Assemble the flange fixture. Based on the relative positions of the upper parts of the outriggers, make the flange fixture for closing. The flange face needs to be machined as a whole on a CNC machine tool, with three sides flush. Fix the outrigger flange to the fixture flange with process bolts. Then assemble the flange fixture to the end of the outrigger according to the structural dimensions. Check the verticality of the upper part of the flange fixture with a theodolite and adjust its verticality. After the dimensions are verified to be qualified, weld the outrigger flange. Step 4: Hoist outrigger C, using the cross beam baseline as a reference for positioning and installation, ensuring that the head and tail of the outrigger are flush with the two lower legs. After adjustment, use clamps to fix outrigger C to the cross beam, and use clamps to fix the head of the outrigger to the flange. Weld the joint between the leg and the cross beam. After the structural correction meets the requirements, perform structural demolding and weld the upper flange of outrigger C. To ensure the relative positional accuracy of outriggers A, B, and C, add fixed diagonal braces. Step 5: After installing and welding the ladders and platforms on legs a, b, and c, sandblast and paint them. Then, rotate the existing structure 90° from a horizontal position to a vertical position. Step 6: Install outrigger d, remove flange fixtures, hoist outrigger d in a vertical position and weld the butt joint with the cross beam, and install the remaining platform and ladder; Step 7: After the large needle wheel support ring is machined, fix the flange of the support leg d to the flange of the support ring with process bolts. Assemble the large needle wheel support ring with the upper flanges of support legs a, b, and c using process bolts. Adjust the position of the flange of support leg d and its upper end. Finally, weld the upper flange of support leg d and remove the fixed support.

[0006] By adopting the above technical solution, the distance between the outriggers can be effectively maintained when they are closed, preventing deformation of the outriggers and ensuring the installation accuracy of the outriggers.

[0007] Preferably, support legs a and b are located on both sides of the center line of the cross beam and are arranged symmetrically.

[0008] By adopting the above technical solution, the legs are arranged symmetrically to each other, which can stabilize the overall legs and effectively improve the stability of the gantry structure.

[0009] Preferably, in step 3, a large needle wheel bearing ring is connected to the support leg via flange bolts.

[0010] By adopting the above technical solution, the connection between the large needle wheel bearing ring and the support leg through bolts can improve the stability and firmness between the large needle wheel bearing ring and the support leg.

[0011] Preferably, in step 3, the flange fixture includes a flange plate and a fixed support. The flange plates are vertically placed and welded together to form a flange cube. A support rod is provided between adjacent flange cubes. The support rod is connected to the side of the flange cube and is connected to the same height as the flange plate. The support leg flange and the bottom surface of the flange cube are connected and fixed.

[0012] By adopting the above technical solution, the flange fixture is welded before being assembled onto the support leg, and it is ensured that the uppermost flange plates of the flange fixture are in the same plane and the support rods are at the same height. This allows for pre-standard preparation, and when the flange fixture is installed on the support leg, it can constrain and fix the support leg, preventing deformation of the support leg.

[0013] Preferably, in step 3, the verticality deviation between the flange surface and the upper surface of the cross beam is no greater than 1 / 1500, and the distance deviation between the flange surface and the upper surface of the cross beam is within the range of -5 to 0 mm. The verticality is adjusted by a hand chain hoist or turnbuckle.

[0014] By adopting the above technical solution, the perpendicularity between the flange face and the crossbeam can be detected to determine whether they are perpendicular.

[0015] Preferably, the fixed diagonal brace in step 4 includes a fixed support flange and an anti-deformation support rod. The fixed support flange is located on the side of the support leg c. The fixed support flange is located at the same position on the support legs a, b, and d. The anti-deformation support rod has a perforated flange plate at its end. The anti-deformation support rod is connected and fixed to the fixed support flange on the support leg by bolts through the perforated flange plate at its end.

[0016] By adopting the above technical solution, the anti-deformation support rod is fixed to the perforated flange plate of the outrigger through the fixed support flange at the end of the anti-deformation support rod, which can effectively prevent the outrigger from deforming.

[0017] Preferably, the fixed diagonal brace in step 4 and the fixed support on the outrigger c have the same structure, and the sides of adjacent outriggers are made up of the same anti-deformation support rod.

[0018] By adopting the above technical solution, the anti-deformation support rod can prevent the outriggers from deforming and improve the installation accuracy of the outriggers.

[0019] Preferably, the ladder and platform in steps 5 and 6 are installed in the upper middle and lower parts of the support legs.

[0020] By adopting the above technical solution, workers can climb up and down the ladder, which facilitates the installation of the outriggers.

[0021] The advantages of this invention are: 1. By installing a flange fixture on the top of the outrigger, the flange fixture can stabilize and correct the top of the outrigger due to its large size, thus preventing inaccuracies caused by its large size and improving the accuracy of the outrigger when it is closed into a gantry.

[0022] 2. By setting a fixed support on the side of the outrigger, the present invention can also support the side of the outrigger, preventing the tilting phenomenon caused by the large size of the outrigger and improving the accuracy of the outrigger when it is closed.

[0023] 3. By setting a cross beam between the legs, the present invention further strengthens the fixation between the legs, thereby preventing displacement at the bottom of the legs. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the gantry frame of the present invention; Figure 2 This is a schematic diagram of the installation of the support legs a, b and the cross beam of the present invention; Figure 3 This is a schematic diagram of the flange tooling installation of the present invention; Figure 4 This is a schematic diagram of the installation of the support leg c of the present invention; Figure 5 This is a schematic diagram of the diagonal brace between the legs of the present invention; Figure 6 This is a schematic diagram of the installation of the auxiliary steels for the outriggers a, b, and c of the present invention; Figure 7 This is a schematic diagram of the structure of the present invention rotated 90°; Figure 8 This is a schematic diagram of the flange tooling removal and support leg d installation of the present invention; Figure 9 This is a schematic diagram of the installation of the large needle wheel support ring of the present invention.

[0025] Among them: 1. Support leg a, 2. Support leg b, 3. Support leg c, 4. Cross beam, 5. Flange fixture, 5-1. Flange plate, 5-2. Support rod, 6. Fixed support flange, 7. Anti-deformation support rod, 8. Perforated flange plate, 9. Ladder, 10. Support leg d, 11. Large needle wheel support ring, 12. Fixture frame. Detailed Implementation

[0026] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0027] like Figure 1-9 As shown, a method for closing a large crane gantry structure includes the following steps: Step 1: Set up the fabrication frame. Based on the actual structure of the gantry, set up the fabrication frame at the fabrication site. The head and tail of the outriggers and the lower part of the cross beam are the main support points. Mark the ground line with the center line of the cross beam as the reference. Step 2: Install and weld support legs a1, b2 and cross beam 4. Assemble the portal legs and cross beam 4. Check the upper and lower positioning dimensions of the support legs according to the ground line. Fix the support legs and cross beam 4 and weld the butt joints. Support legs a1 and b2 are located on both sides of the center line of cross beam 4 and are symmetrically arranged. The support legs are symmetrically arranged with each other, which can stabilize the overall support legs and effectively improve the stability of the portal frame structure. Step 3: Assemble flange fixture 5. Based on the relative positions of the upper parts of the outriggers, fabricate flange fixture 5 for closing. The flange surface needs to be machined as a whole on a CNC machine tool, with three sides flush. Fix the outrigger flange to the fixture flange with process bolts. Then assemble the flange fixture to the end of the outrigger according to the structural dimensions. Check the verticality of the upper part of the flange fixture with a theodolite and adjust its verticality. After the dimensions are verified to be qualified, weld the outrigger flange. A large needle wheel bearing ring 11 is connected to the outrigger through flange bolts. The connection between the large needle wheel bearing ring 11 and the outrigger through bolts can improve the stability and firmness between the large needle wheel bearing ring 11 and the outrigger. The flange fixture includes flange plate 5-1 and fixed support 5-2. The flange plates 5-1 are placed vertically and welded together to form a flange cube. Support rods 5-2 are provided between adjacent flange cubes. The support rods 5-2 are connected to On the side of the flange cube, the support rod 5-2 is connected to the flange plate 5-1 at the same height. The support leg flange and the bottom surface of the flange cube are connected and fixed. The flange fixture 5 is welded before being assembled onto the support leg, and it is ensured that the uppermost flange plates of the flange fixture 5 are in the same plane, and the support rod 5-2 is also at the same height. This allows for pre-standard preparation. When the flange fixture 5 is installed on the support leg, it can constrain and fix the support leg to prevent deformation. The verticality, i.e., the deviation of the flange surface from the horizontal level of the cross beam, is no more than 1 / 1500. The distance deviation from the flange surface to the upper surface of the cross beam is within the range of -5~0mm. The verticality is adjusted by a hand-operated hoist or turnbuckle. The verticality can be checked by measuring the verticality between the flange surface and the cross beam to determine whether it is vertical. Step 4: Hoist outrigger C3, using the cross beam 4 as a reference for positioning and installation, ensuring that the head and tail of the outrigger are flush with the two lower legs. After adjustment, use clamps to fix outrigger C3 to the cross beam 4, and use clamps to fix the head of the outrigger to the flange. Weld the joint between the leg and the cross beam 4. After the structural correction meets the requirements, perform structural demolding and weld the upper flange of outrigger C3. To ensure the relative positional accuracy of outriggers A1, B2, and C3, add fixed diagonal bracing. The fixed diagonal bracing includes a fixed support flange 6 and an anti-deformation support rod 7. The fixed support flange 6 is located on the side of outrigger C3 and on outrigger A1. At the same position as outriggers b2 and d10, the anti-deformation support rod 7 has a perforated flange plate 8 at its end. The anti-deformation support rod 7 is connected and fixed to the fixed support flange 6 on the outrigger by bolts through the perforated flange plate 8 at its end. The anti-deformation support rod 7 can effectively prevent the outrigger from deforming on the side. The fixed diagonal brace and the fixed support on outrigger c3 have the same structure. The side of adjacent outriggers is the same anti-deformation support rod 7. The anti-deformation support rod 7 can prevent the outrigger from deforming and improve the installation accuracy of the outrigger. Step 5: After installing and welding the ladder 9 and platform on the support legs a1, b2, and c3, sandblast and paint them. Turn the existing structure 90° and adjust it from a horizontal to a vertical position. Step 6: Install outrigger d10, remove flange fixtures, hoist outrigger d10 in a vertical position and weld the butt joint with cross beam 4, and install the remaining platform and ladder 9; Step 7: After the large needle wheel support ring 11 is machined, use process bolts to fix the flange of the support leg d10 to the flange of the support ring. Assemble the large needle wheel support ring 11 with the upper flanges of the support legs a1, b2, and c3 using process bolts, and adjust the position of the flange of the support leg d10 and its upper end. Finally, weld the upper flange of the support leg d10 and remove the fixing support. When closing, the gap between the support legs can be effectively maintained to prevent deformation of the support legs and ensure the installation accuracy of the support legs.

[0028] In steps 5 and 6, ladders 9 and platforms are installed at the upper middle and lower parts of the outriggers. Workers can climb up and down ladders 9 to facilitate the installation of the outriggers.

[0029] Those skilled in the art should understand that the embodiments of the present invention described above and shown in the accompanying drawings are merely examples and do not limit the present invention; the objectives of the present invention have been fully and effectively achieved. The functions and structural principles of the present invention have been demonstrated and explained in the embodiments, and any modifications or variations of the embodiments of the present invention may be made without departing from the stated principles.

Claims

1. A method for assembling a large crane gantry structure, characterized in that, Includes the following steps: Step 1: Set up the fabrication frame. Based on the actual structure of the gantry, set up the fabrication frame at the fabrication site. The head and tail of the outriggers and the lower part of the cross beam are the main support points. Mark the ground line with the center line of the cross beam as the reference. Step 2: Install and weld support legs a, support legs b and cross beams, assemble the door legs and cross beams, check the upper and lower positioning dimensions of the support legs according to the ground line, fix the support legs and cross beams, and weld the joint between them. Step 3: Assemble the flange fixture. Based on the relative positions of the upper parts of the outriggers, make the flange fixture for closing. The flange face needs to be machined as a whole on a CNC machine tool, with three sides flush. Fix the outrigger flange to the fixture flange with process bolts. Then assemble the flange fixture to the end of the outrigger according to the structural dimensions. Check the verticality of the upper part of the flange fixture with a theodolite and adjust its verticality. After the dimensions are verified to be qualified, weld the outrigger flange. The flange fixture includes a flange plate and a fixed support. The flange plates are vertically placed and welded together to form a flange cube. A support rod is provided between adjacent flange cubes. The support rod is connected to the side of the flange cube and is connected to the same height as the flange plate. The leg flange is fixedly connected to the bottom surface of the flange cube. Step 4: Hoist outrigger C, using the cross beam baseline as a reference for positioning and installation, ensuring that the head and tail of the outrigger are flush with the two lower legs. After adjustment, use clamps to fix outrigger C to the cross beam, and use clamps to fix the head of the outrigger to the flange. Weld the joint between the leg and the cross beam. After the structural correction meets the requirements, perform structural demolding and weld the upper flange of outrigger C. To ensure the relative positional accuracy of outriggers A, B, and C, add fixed diagonal braces. The fixed diagonal brace includes a fixed support flange and an anti-deformation support rod. The fixed support flange is located on the side of the support leg c. The fixed support flange is located at the same position on the support legs a, b, and d. The anti-deformation support rod has a perforated flange plate at its end. The anti-deformation support rod is connected and fixed to the fixed support flange on the support leg by bolts through the perforated flange plate at its end. The fixed diagonal brace and the fixed support on the outrigger c have the same structure, and the sides of adjacent outriggers are made up of the same anti-deformation support rod. Step 5: After installing and welding the ladders and platforms on legs a, b, and c, sandblast and paint them. Then, rotate the existing structure 90° from a horizontal position to a vertical position. Step 6: Install outrigger d, remove flange fixtures, hoist outrigger d in a vertical position and weld the butt joint with the cross beam, and install the remaining platform and ladder; Step 7: After the large needle wheel support ring is machined, fix the flange of the support leg d to the flange of the support ring with process bolts. Assemble the large needle wheel support ring with the upper flanges of support legs a, b, and c using process bolts. Adjust the position of the flange of support leg d and its upper end. Finally, weld the upper flange of support leg d and remove the fixed support.

2. The closing method for a large crane gantry structure according to claim 1, characterized in that: The outriggers a and b are located on both sides of the center line of the cross beam and are arranged symmetrically.

3. The closing method for a large crane gantry structure according to claim 1, characterized in that: In step 3, a large needle wheel bearing ring is connected to the support leg by flange bolts.

4. The closing method for a large crane gantry structure according to claim 1, characterized in that: In step 3, the verticality, i.e., the deviation between the flange surface and the upper surface of the cross beam, is no greater than 1 / 1500, and the distance deviation between the flange surface and the upper surface of the cross beam is within the range of -5~0mm. The verticality is adjusted by a hand chain hoist or turnbuckle.

5. The closing method for a large crane gantry structure according to claim 1, characterized in that: The ladders and platforms in steps 5 and 6 are installed in the upper middle and lower parts of the support legs.

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