Boom main arm composite structure, crane, and boom main arm composition method

Abstract

The invention discloses a boom main arm composite structure, a crane, and a boom main arm composition method. The boom main arm composite structure comprises a first-section arm, a second-section arm, a third-section arm..., and an Nth-section arm. N is a natural number which is not smaller than 2. Under a full outrigger condition, with the elongation length of the Nth-section arm relative to the (N-1)th-section arm, stress levels on all the section arms tends to be the same. According to the invention, according to the stress under the full outrigger condition, elongation lengths of different section arms are changed, such that the elongation lengths of the section arms are different under the full outrigger condition, and the stresses on the section arms under the full outrigger condition are balanced. Therefore, boom lifting performance is further improved. Also, boom stiffness is improved to a certain extent.

Description

technical field [0001] The invention relates to the technical field of cranes, in particular to a combination structure of a main boom of a boom, a crane, and a method for combining a main boom of a boom. Background technique [0002] For large-tonnage cranes, the main boom of the boom is composed of multi-section arms. For example, the boom of a certain crane is composed of the first section arm, the second section arm, the third section arm, the fourth section arm, Sectional arm and sixth section arm. In addition to the last arm, the upper cover of each arm generally has four arm pin holes, which are the pin hole of the first arm, the pin hole of the second arm, the pin hole of the third arm and the pin hole of the fourth arm. The position combination of the arm pin hole can achieve the combination of different arm lengths. [0003] Under the condition of full extension of the main boom, the full extension of each section of the boom is the same, and the combined structu...

AI Technical Summary

Problems solved by technology

However, this telescopic combination structure usually causes a large stress area in the lap joints of the second and third arms, while the stress at the lap joints of the last five and six arms is relatively small.

[0004] That is to say, for the jib main boom composed of multi-section jibs, when all the jib sections are 100% extended, some sections of the jib will appear due to excessive stress in the local area, resulting in partial lifting performance of the fully extended jib. Areas with low or high stress are prone to instability and accidents

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