Preparation process of sharp-corner square tube for outer cantilever of tower crane

Abstract

The invention relates to a manufacturing technology of a sharp-corner square tube for an outer cantilever of a tower crane. The manufacturing technology comprises the following steps that S1, a tube blank is pretreated; s2, upper surface forming machining is conducted, specifically, the H edge of the upper surface of the pipe blank subjected to edge milling is folded through a first flat roller machine, and R1 is folded to 124 degrees; s3, forming machining of the lower surface and the two side faces, wherein R2 and R3 on the two sides of the bottom are pressed and folded to 118 degrees; s4, forming machining of the left side face is conducted, specifically, a blind angle R2 opposite to the weld joint is pressed and folded to 112 degrees through an oblique insertion roller; s5, angle positioning of the upper surface and the two side faces, wherein R2 and R3 of the pipe blank are continuously pressed and folded to 94 degrees, and R1 is pressed and folded to 96 degrees; s6, extrusion and welding are conducted, specifically, the right surface edge F and the upper surface edge H are extruded and overlapped, meanwhile, high-frequency heating welding is conducted, and a pipe shape is formed; and S7, welding seam planing is conducted, specifically, the welding seam is planed through a scraper. By improving the forming process, a 90-degree right angle is formed, so that the trolley walks smoothly; during machining, welding, alignment and leveling are better, and the working efficiency is improved; and the installation efficiency is greatly improved.

Description

technical field [0001] The invention relates to the technical field of crane manufacturing, in particular to a preparation process of a sharp-angled square tube for the outer cantilever of a tower crane. Background technique [0002] Because the two sides of the outer cantilever of the existing general-purpose tower crane are ordinary square tubes, the specifications and sizes of the outer cantilever vary from large to small (the first section is 135 square meters, the second section is 118 square meters, the third section is 108 square meters, the fourth section, 98 square meters Square, fifth section 86 square, sixth section 76 square), due to different specifications, sizes, and different wall thicknesses, the R angle changes greatly, resulting in uneven and uneven The phenomenon of rubbing the table will eventually cause the trolley to run unsteadily, jump, and make loud noises. In addition, during the processing, there is a large amount of R corner welding and the weld...

AI Technical Summary

Problems solved by technology

[0002] Because the two sides of the outer cantilever of the existing general-purpose tower crane are ordinary square tubes, the specifications and sizes of the outer cantilever range from large to small (the first section is 135 square, the second section is 118 square, the third section is 108 square, the fourth section, 98 Square, fifth section 86 square, sixth section 76 square), due to different specifications, sizes, and different wall thicknesses, the R angle changes greatly, resulting in uneven and uneven The phenomenon of rubbing the table will eventually cause the trolley to run unsteadily, jump, and make loud noises, etc.

In addition, in the process of processing, there is a large amount of R corner welding and the welding speed is slow; it is easy to make mistakes in leveling and leveling, and the processing efficiency is low; rework often occurs when the outer cantilever is installed; The traveling pulley of the trolley has a small contact area with the R angle of the square tube, wears quickly, and is easy to wear out. Therefore, the use of square tubes for the outer cantilever of existing tower cranes has great disadvantages

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