SU1632928A1 - Telescopic boom of crane - Google Patents

Description

one

(21) 4361747/11; 4411952/11

(22) 01/08/88

(46) 03/07/91. Bul N 9

(71) The head special design and technology bureau of crane cranes of the Production Association Truck crane

(72) A.A. Kokorin, G.S.Kalbenina, V.A.Artyukov and A.A.M.

(53) 621.874 (088.8)

(56) USSR author's certificate

No. 627068, Clo B 66 C 23/68, 1977.

(54) TELESCOPIC CRANE ARROW (57) The invention relates to a lifting and transport machinery, in particular to telescopic booms of lifting machines. The purpose of the invention is to increase the load capacity. The goal is achieved by increasing the stability of the boom to longitudinal and transverse bends due to the locations of the highest concentration of stresses in the form of hollow triangles formed by the main profile 5 and the sheet 6 or the main profile 5 and the corner installed outside. 3 il.

FIELD OF THE INVENTION The invention relates to lifting and transport machinery, in particular, to telescopic booms of lifting machines.

The purpose of the invention is to increase the load capacity.

FIG. 1 shows a telescopic boom, general view; in fig. 2 is a section A-A in FIG. one; in fig. 3 - telescopic boom, option.

The telescopic boom contains a fixed 1 and sliding 2 box sections. Section 2 rests on the lower 3 and upper 4 supports. Each section is made with a rectangular beam with horizontal or inclined shelves. For example (figure 2), a section with inclined shelves consists of two trough-shaped profiles 5, welded with a longitudinal seam. Trough-shaped profile 5 is made of a vertical wall and an inclined shelf at an angle to the horizon up to 20U. Prior to welding the profiles 5, at the point of transition from the vertical wall to the shelf, the sheet element 6 is welded from the inside, thus forming a longitudinal along with reinforcement, which can be formed if the sheet element 7 is welded outside (Fig. 3).

Telescopic boom works as follows.

When loading the boom in the plane of suspension of the load, the force arising in the supports 3 or 4 is transmitted to the side walls, forming in them a local stress that quickly decays along the wall length, but is comparable in value to the stress from bending the boom like a beam.

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Such a combination of loads in order to satisfy the strength condition requires an increased wall thickness and, therefore, an increase in the boom design. When there is a reinforcement sa, which represents a hollow triangle in cross section, the values of local stress drop sharply, which allows the overall boom profile to be made of a smaller thickness. Since the moments acting on the wall and the shelf are the same, the voltage on the shelf decreases.

In addition, reducing the width of the flat walls contributes to their local stability.

Longitudinal sa rigidity should be located in areas of local loads, for example, in

Vision section - on the upper shelf, in the last sliding section - on the lower shelf, in the intermediate sections - on the upper and lower shelves.

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Claims (1)

Invention Formula A telescopic boom of a crane containing fixed and sliding sections of box-section, having in the interface areas of the upper and lower walls with side mounted on them by means of one-piece connections sheet elements forming hollow longitudinal reinforcements with sections of the sections, placed on the fixed and sliding intermediate sections along the upper edges, and the extension of the outer section - along the lower edges, characterized in that, in order to increase the load capacity, on the retractable intermediate section along the lower x ribs secured by additional gain ca, wherein each of the chord in the cross section has the shape of a hollow triangle. Faye. Fie.2