RU2094360C1 - Crane jib - Google Patents

Abstract

FIELD: lifting engineering. SUBSTANCE: pipe mounted on the jib is made up as arc-like tubular portions conjugated with each other in series. The bend of the concave side of the portions is defined by a relationship presented in the invention description. EFFECT: enhanced reliability. 2 cl, 2 dwg

Description

 The invention relates to cranes and can be used in the manufacture of crane bridges using welding units in various industries.

A known construction of a crane bridge, consisting of a tubular beam welded from several pipes having thickened walls in the middle part [1]
A disadvantage of the known construction of the crane bridge is that the design of the tubular beam, consisting of several pipes in order to increase the moment of inertia, has a thickened shape at the maximum load, therefore, the beam part of the crane, for example, gantry, has an increased metal consumption and weight.

Closest to the proposed technical essence is the construction of a crane bridge containing a pipe located on the ride beam, as well as kerchiefs attached to the ride beam and pipe [2]
The disadvantage of this design of the crane bridge is that during the operation of the crane the pipe undergoes a large deflection, especially at maximum load, which leads to a loss of stability of the crane bridge, and therefore does not allow to increase the crane's carrying capacity.

 The purpose of the invention is to increase the lifting capacity of the crane and reduce the stability loss of the bridge.

The goal is achieved in that in the construction of the crane bridge containing the ride beam, a pipe mounted on the ride beam along it and kerchiefs located on both sides of the pipe and rigidly connected with the latter and the ride beam, characterized in that the pipe is made of arcuate sections, sequentially interconnected and facing their concave surfaces to the ride beam, with each arcuate section of the pipe is made with a deflection defined by the dependence
f _tr. f _max / n,
where f _tr.uch. deflection of each arcuate section of the pipe, mm;
f _max maximum deflection of the bridge at the maximum permissible load, mm;
n the number of arched sections of the pipe.

 The kerchiefs are located at the junctions of the arcuate sections of the pipe.

 In FIG. 1 schematically shows the construction of a crane bridge; in FIG. 2 is a section AA in FIG. one.

The construction of the crane bridge contains a pipe 2 mounted on the ride beam 1, which is made in the form of "n" arcuate tubular sections connected in series: A, B, C, D, E. Each tubular section has a deflection
f _tr. f _max / n,
where f _tr.uch. deflection of each pipe section, mm;
f _max maximum deflection of the bridge at the maximum permissible load, mm;
n the number of arched sections of the pipe.

 In this case, the scarves 3, rigidly connecting the pipe 2 with the driving beam 1, are installed in the interface between the arcuate tubular sections.

 The design of the bridge crane operates as follows.

A truck with a load (not shown) is moved along the driving beam 1. During the movement, the load causes a deflection of the crane bridge f _max bridge 60 mm.

The bridge has 10 tubular sections, then
f _tr. f _max / n 60/10 6 mm
Due to the fact that the crane bridge pipe is made of arcuate tubular sections, longitudinal compression strains appear in the bridge structure. It is known that arcuate (strong structures withstand significantly greater loads than straight ones (Orlov P.I., Fundamentals of Design, vol. 1, M. Mechanical Engineering, 1988, p. 153).

 Thus, the load (load) will create two types of deformations in the structure: tensile bending and compressive longitudinal, and therefore the total strain in the proposed design will be less than the strain of the bridge having a straight pipe, since tensile and compression strains have different signs, and therefore deductible.

 Thus, the proposed design of the crane bridge allows, in comparison with the prototype, to increase the carrying capacity of the crane by reducing the total deformation of the structure, and the installation of scarves in the interface between the arcuate tubular sections, reduces the possibility of loss of stability of the bridge.

Claims (2)

1. The design of the crane bridge containing a riding beam, a pipe mounted on a riding beam along it, and scarves located on both sides of the pipe and rigidly connected with the latter and the riding beam, characterized in that the pipe is made of arcuate sections sequentially mated between themselves and facing their concave surfaces to the driving beam, while each arcuate section of the pipe is made with a deflection defined by the dependence
f _tr.uch f _{max bridge} / h,
where f _{t p . at h the} deflection of each arcuate section of the pipe, m;
f _{m a x} bridge maximum deflection of the bridge at the maximum permissible load, mm;
n the number of arched sections of the pipe.  2. The construction according to claim 1, characterized in that the kerchiefs are located at the interface between the arcuate sections of the pipe.

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