Structural Features and Key Points of Large Truss Girder Welding Machine

1. Truss girder welding machine structural characteristics and main technical requirements
The lower interrogation platform is the largest active part connected to the main tower. It is mainly composed of hinge seat, main truss, truss and other structures, total weight: 244.281 tons, external dimensions: 9100X22000X24470mm, truss assembly is symmetrical, there are all strength bolts connected between main trusses, between trusses, between main truss and truss. After assembling, the main truss is clamped to the end of the sill. The design requires 40mm upturn. After the six main trusses are assembled and welded, the diagonal dimensions of 21000×22000mm are required: 304411±10m, 30386±10m, ie: the six main trusses are assembled and welded into parallelograms. All the working surfaces of connecting seat eg. the track on the main trusses and the truss should be on the same plane.

2. Manufacturing difficulties and key

The main part of the lower A-turn platform is made of angle steel, channel steel and steel pipe etc. through the joint plate. The number of components is big, and there is no assembly reference surface. The assembly is cumbersome and complicated. The overall size is large after assembly and the precision is not easy to guarantee. The main truss 12 pieces. It is an ultra-long welded structural member: 2000×3500×24000m. The welded structure is small in rigidity and the welding is easy to deform. Some joint machining process is completed before assembly and welding, so it is tremendously difficult to control the welding deformation; a large number of high-strength bolts are connected between the main trusses and the trusses to ensure the accuracy of the boring of the drilled holes, and the difficulty is also great. Therefore, how to ensure the dimensions of the trusses and main trusses after assembly and welding, reduce the welding deformation, ensure the accurate connection of high-strength bolts.  And to ensure that after the truss and truss, the main truss and the main truss finally assembled the overall shape sizes meet the design requirements (the tolerance of the diagonal size, the tolerance of the section size, the upturn value of 40mm, and the connection seat and addition of each face of the main trusses are on the same plane, etc.) are the key to theassembly & welding technology and manufacturing.