Method for manufacturing or transforming main beams of crane

Abstract

Provided is a method for manufacturing or transforming main beams of a crane. An I-shaped steel support and reinforcing ribs are welded between a main beam midspan beam and supporting frames; tensioners are mounted at the top ends of the supporting frames and the tail end of a main beam cantilever through connecting seats, and are tensioned through a tensioning system, so that the camber of the main beam midspan beam meets the standard requirement, and the upwarping degree of the effective cantilever position of the main beam cantilever ranges from 0.9/350 to 1.4/35. According to the method for manufacturing or transforming the main beams of the crane, processing and manufacturing are easy, cost is low, and construction is convenient; the method is suitable for being used for manufacturing or transforming main beams of cranes of any tonnage, and especially suitable for manufacturing and transforming of portal cranes in the port and shipbuilding industry. The camber difference of the two manufactured or transformed main beams of the crane is kept between 0 to 1 mm, the main beams of the crane are always kept at any value within the international range, steel is saved, and cost is reduced by 15% to 20 %; the method conforms to the national energy saving and emission reducing policy, and the service life of the crane is prolonged.

Description

technical field [0001] The invention relates to a crane manufacturing process, in particular to a method for manufacturing or transforming a main girder of a crane. Background technique [0002] Bridge and gantry cranes are special equipment widely used by industrial and transportation material enterprises. In order to ensure the performance requirements of the crane and avoid the phenomenon of "climbing" and "rolling" of the electric trolley, the main girder of the crane must have a certain degree of camber , my country's crane manufacturing technical standards stipulate the camber in the middle span of the main girder of the crane when the main girder of the crane is unloaded. (L K is the span of the crane, that is, the wheel span of the crane cart). Due to various reasons in the design, manufacture and use, the main girder of the crane will be deflected and deformed. The hazards are: the cart gnaws on the rail, the trolley "climbs" and "rolls", the lifting capacity drop...

AI Technical Summary

Problems solved by technology

Due to various reasons in the design, manufacture and use, the main girder of the crane will be deflected and deformed. The hazards are: the cart gnaws on the rail, the trolley "climbs" and "rolls", the lifting capacity drops, and even accidents occur. , endangering safety

[0003] The cantilever of the main girder of the gantry crane should be upwarped, and the upwarping degree at the effective cantilever should be (0.9 / 350—1.4 / 350) L is the length of the cantilever, and the downward deflection of the cantilever will cause the trolley to "slip" and easily cause accidents and endanger safety.

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